docs: add community guidelines and navigation structure

README.md

@@ -170,20 +170,10 @@ Normal builds use the **latest published spec release**, not the spec's `main` b
 
 ## Contributing
 
-Pull requests are welcome.
-
-- Sign your commits: `git commit -s` (DCO is required)
-- Use [Conventional Commits](https://www.conventionalcommits.org/) for PR titles,
-  for example `docs: fix typo on the model page`
-- Run `make cleanup` before committing
-
-Come talk to us first if you're planning something large:
-
-- **Slack:** [#gemara](https://openssf.slack.com/archives/C09A9PP765Q) on OpenSSF Slack
-- **Meetings:** every other Thursday — see the
-  [OpenSSF calendar](https://calendar.google.com/calendar/u/0?cid=czYzdm9lZmhwNWk5cGZsdGI1cTY3bmdwZXNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ)
-
-Maintainers are listed in `_data/maintainers.yml`.
+Pull requests are welcome. See the
+[Contributing guide](https://gemara.openssf.org/community/contributing) on the
+site for the full guidelines, including sign-off requirements and AI
+attribution expectations.
 
 ---
 

_data/navigation.yml

@@ -2,6 +2,13 @@
   url: /
 - title: Community
   url: /community/
+  children:
+    - title: Overview
+      url: /community/
+    - title: Contributing
+      url: /community/contributing
+    - title: Maintainers
+      url: /community/maintainers
 - title: Roadmap
   url: /roadmap
 - title: Tutorials

_includes/header.html

@@ -38,7 +38,18 @@ <h1 class="site-title">
 
       <div class="trigger">
         {%- for item in site.data.navigation -%}
+          {%- if item.children -%}
+          <details class="nav-dropdown">
+            <summary class="page-link">{{ item.title | escape }}</summary>
+            <div class="nav-dropdown-menu">
+              {%- for child in item.children -%}
+                <a class="page-link" href="{{ child.url | relative_url }}">{{ child.title | escape }}</a>
+              {%- endfor -%}
+            </div>
+          </details>
+          {%- else -%}
           <a class="page-link" href="{{ item.url | relative_url }}">{{ item.title | escape }}</a>
+          {%- endif -%}
         {%- endfor -%}
       </div>
     </nav>

assets/css/style.scss

@@ -582,6 +582,44 @@ a[href^="http"]:not([href*="gemara"]):not([href*="openssf"]):not(.social-media-l
     }
   }
 
+  .nav-dropdown {
+    position: relative;
+
+    summary {
+      cursor: pointer;
+      list-style: none;
+
+      &::-webkit-details-marker {
+        display: none;
+      }
+
+      &::after {
+        content: "▾";
+        margin-left: var(--spacing-xs);
+        font-size: 0.75em;
+      }
+    }
+
+    .nav-dropdown-menu {
+      display: flex;
+      flex-direction: column;
+      position: absolute;
+      top: 100%;
+      left: 0;
+      min-width: 160px;
+      padding: var(--spacing-xs);
+      background: var(--color-bg-primary);
+      border: 1px solid var(--color-border);
+      border-radius: var(--radius-sm);
+      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
+      z-index: 10;
+
+      .page-link {
+        padding: var(--spacing-xs) var(--spacing-sm);
+      }
+    }
+  }
+
   @media screen and (max-width: 768px) {
     position: relative;
 
@@ -625,6 +663,17 @@ a[href^="http"]:not([href*="gemara"]):not([href*="openssf"]):not(.social-media-l
       width: 100%;
       padding: var(--spacing-sm) var(--spacing-md);
     }
+
+    .nav-dropdown {
+      width: 100%;
+
+      .nav-dropdown-menu {
+        position: static;
+        border: none;
+        box-shadow: none;
+        padding: 0 0 0 var(--spacing-md);
+      }
+    }
   }
 }
 

community/contributing.md

@@ -0,0 +1,66 @@
+---
+layout: page
+title: Contributing
+nav-title: Contributing
+---
+
+Thanks for your interest in contributing to Gemara! Contributions of all
+kinds are welcome including docs, schemas, SDKs, examples, and ideas. This page
+covers a few things worth knowing before you open a pull request, including
+how we like AI-assisted work to be attributed.
+
+## Getting started
+
+- Sign off your commits with `git commit -s` (see [DCO](#dco) below).
+- Use [Conventional Commits](https://www.conventionalcommits.org/) for PR
+  titles, for example `docs: fix typo on the model page`.
+- Run `make cleanup` before committing to clear out generated files.
+
+Planning something larger? Come say hello first. We're happy to help shape
+the idea:
+
+- **Slack:** [#gemara](https://openssf.slack.com/archives/C09A9PP765Q) on OpenSSF Slack
+- **Meetings:** every other Thursday — see the [OpenSSF calendar](https://calendar.google.com/calendar/u/0?cid=czYzdm9lZmhwNWk5cGZsdGI1cTY3bmdwZXNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ)
+
+## DCO
+
+Gemara uses the [Developer Certificate of Origin](https://developercertificate.org/),
+so please sign off your commits with `git commit -s`. The sign-off says that
+you wrote the change, or otherwise have the right to submit it. So it should
+be yours, even when an AI tool helped you write it.
+
+## Working with AI
+
+AI-assisted contributions are welcome. We just ask that you be open about
+where AI was involved, so reviewers and future maintainers understand what
+they're looking at. Please refer to the Linux Foundation's [Generative AI Policy](https://www.linuxfoundation.org/legal/generative-ai)
+for additional guidance.
+
+### Commits
+
+When AI helped author a commit, add an `Assisted-by:` trailer naming the tool:
+
+```
+Assisted-by: Claude Code <noreply@anthropic.com>
+```
+
+Please don't use `Co-authored-by:` for AI tools (this is blocked by our branch protections).
+The DCO sign-off is a statement made by a person, so co-authorship should reflect the humans
+involved.
+
+### PRs, issues, and comments
+
+If an AI generated or largely drafted a PR description, issue, or comment,
+add a 🤖 so it's clear which text is AI-generated and which is yours.
+
+### Understanding what you contribute
+
+Whether a change is hand-written or AI-assisted, the goal is the same: you
+should understand it well enough to walk someone through it. A good rule of
+thumb is to imagine explaining the change months from now. You might not
+remember every function name, but the reasoning, the design, and the
+packages it relies on should still feel like yours.
+
+If a change gets that kind of understanding, it's in good shape. If it
+doesn't yet, it's worth spending a bit more time with it before asking for a
+review.

community/index.md

@@ -9,12 +9,8 @@ nav-title: Community
 - **Slack:** [#gemara](https://openssf.slack.com/archives/C09A9PP765Q) on OpenSSF Slack
 - **Meetings:** Bi-weekly on alternate Thursdays - see the [OpenSSF calendar](https://calendar.google.com/calendar/u/0?cid=czYzdm9lZmhwNWk5cGZsdGI1cTY3bmdwZXNAZ3JvdXAuY2FsZW5kYXIuZ29vZ2xlLmNvbQ)
 - **GitHub:** [gemaraproj/gemara](https://github.com/gemaraproj/gemara)
-
-### Meet the Maintainers
-
-{% for maintainer in site.data.maintainers.maintainers %}
-- {{ maintainer.name }}, {{ maintainer.organization }} (@{{ maintainer.github }})
-{% endfor %}
+- **Contributing:** see the [Contributing guide](/community/contributing)
+- **Maintainers:** meet the people behind Gemara on the [Maintainers page](/community/maintainers)
 
 ### Projects and Working Groups 
 

community/maintainers.md

@@ -0,0 +1,16 @@
+---
+layout: page
+title: Maintainers
+nav-title: Maintainers
+---
+
+Gemara is maintained by a group of contributors across the community. These
+folks review contributions, guide the project's direction, and are happy to
+help you get started.
+
+{% for maintainer in site.data.maintainers.maintainers %}
+- {{ maintainer.name }}, {{ maintainer.organization }} (@{{ maintainer.github }})
+{% endfor %}
+
+Want to get involved? See the [Contributing guide](/community/contributing)
+or come find us on [Slack](https://openssf.slack.com/archives/C09A9PP765Q).