Contribution guide

CONTRIBUTING.md

@@ -0,0 +1,35 @@
+# Contributing to xc
+
+Thank you for using `xc` and for your interest in contributing. Please take a moment to get familiar with our guidelines.
+
+## Be Courteous
+We expect you to read and follow our [Code of Conduct](./CODE_OF_CONDUCT.md) and to conduct yourself always in a way that creates a positive environment and clearly demonstrates your courtesy.
+
+## Use GitHub Issues
+
+We track and discuss work using Issues. Please [open an issue](https://github.com/joerdav/xc/issues/new/choose) to discuss changes before sending a pull request. We may close a PR without review if it's opened without discussion, especially by an unknown contributor. Whether we choose to review a PR is based on a judgment call about the maintenance burden it adds.
+
+## Write Tests, Maintain Coverage
+
+We expect authors of net-new code to provide tests covering the new code. Prior to merging, CI will verify that all tests pass and that coverage equals or exceeds the pre-merge state.
+
+## Document Your Work
+
+We expect contributors to keep documentation (in `docs/`) up to date, reflecting all substantive changes. Use `xc run-docs` (requires `hugo`) to verify that your changes build successfully & look as you expect.
+
+# HOWTOs
+
+## Add Support For A Markup Language
+We aim to support popular, stable, lightweight plain-text markup languages. Our priorities for language support:
+- New languages should work as similar to the Markdown implementation as possible
+- Users should be able to read and maintain tasks without writing excessive markup or understanding implicit behavior
+- New languages should be ubiquitous enough that it makes sense for the project to take on the maintenance burden to support them going forward. See for example the [list of markup languages supported by GitHub](https://github.com/github/markup/blob/master/README.md#markups) to get a rough idea.
+
+Steps to add support:
+- Create a GitHub issue to propose the addition and discuss
+- Fork the repo and add a new parser module for the new language under `parser/`  
+  *It may be advantageous to copy an existing parser and modify it to fit the particulars of the new addition.*
+- [Write tests](#write-tests-maintain-coverage) & test fixtures in your parser module that cover all the same cases as are present in `parser/parsemd/testdata/`
+- Update the `cmd/xc/` module to use your parser
+- [Document your work](#document-your-work)
+- Send a PR for your changes, linking the issue you created previously

README.md

@@ -34,6 +34,9 @@ tasks) as a source of useful commands for the project.
 
 Installation instructions are described at <https://xcfile.dev/getting-started/#installation>.
 
+# Contributing
+Find our guidelines & HOWTOs at [CONTRIBUTING.md](https://github.com/joerdav/xc/blob/main/CONTRIBUTING.md).
+
 # Features
 
 - Tasks defined in Markdown or org-mode files as code blocks.