README — install, supported syntaxes, MVP limitations

[RE-codes]

Story

As a vault user installing this plugin, I should be told up-front what works, what doesn't, and what's deferred — so I don't file bugs against intentional gaps.

Tasks

• Update README.md (create if missing) with sections:
  • What this plugin does — one paragraph: GFM kebab-case fragment resolution in Reading mode, Live Preview, Source mode.
  • Install — symlink/copy install instructions for personal use.
  • Supported syntaxes — [x](#h), [x](file.md), [x](file.md#h), percent-encoded paths.
  • Known limitations (MVP) — bullet list pulled from accepted-limitation outcomes:
    • Hover preview may show "unable to find" for GFM fragments (until Epic 12 P3).
    • Context menu "Open in new tab" / "Open to the right" do not navigate to the fragment (until Epic 12 P3).
    • Duplicate-heading suffixes (#foo-1, #foo-2) highlight only the heading, not heading+children, after the first occurrence.
    • Linux case sensitivity for cross-platform filenames.
    • Source-mode middle-click has a brief delay before the new tab highlights the target.
    • Source-mode parser handles common inline-link forms (P2b); reference, collapsed-reference, shortcut-reference, and multiline-title links not supported in Source mode.
    • Desktop-only.
  • Uninstall — toggle off in Community Plugins, optionally delete the plugin folder.
• Cross-link from each accepted-limitation issue to this section.

Acceptance Criteria

• README exists with all listed sections.
• Each MVP-accepted or deferred limitation appears.
• README references the public-release Epic 12 issues for users who want fixes.

References

• Parent epic: Epic: MVP Completion Gate #98
• plan/gfm-fragment-links-plan.md § Step 10