Bump docfx to 2.81.0

[masa-iwm]

Requested by masa · project thread

What this changes

Before: docfx is pinned to 2.80.1. Dependabot's update to 2.81.0 (#7, rewritten after #10 landed) again drops the final newline from .config/dotnet-tools.json, which .editorconfig (insert_final_newline = true) requires.

After: docfx is pinned to 2.81.0 and the file keeps its final newline. This replaces #7; Dependabot closes it once main carries 2.81.0.

How: a one-line version change. PR CI does not run docfx (the Docs workflow runs on pushes to main only), so the site was built locally from main with 2.80.1 and with 2.81.0 and compared: both exit 0, the same 9 warnings, and every generated page is byte-identical. The only differences are the template's rebuilt JS bundles under public/ and a new docfx_version field in manifest.json. The 2.81.0 upgrade note (a timeout for custom JavaScript template preprocessors) does not apply: docfx/docfx.json uses only the built-in default and modern templates.

Checklist

The long form of each gate is in
CONTRIBUTING.md.

• dotnet build is warning-free. Not affected: only the docfx tool pin changes; CI covers the build.
• The generator agrees with what is committed. Not affected; CI verify covers it.
• Nothing under src/*/Generated/ was hand-edited.
• Census counts were changed deliberately if the emitted surface moved. Not affected.
• Nothing the published baseline shipped was removed or reshaped. Not affected.
• dotnet test passes. Not run locally (no project code changes); left to the CI matrix.
• NativeAOT smoke checked when the runtime or marshalling was touched. Not touched.
• English throughout.
• Commits are in the imperative mood, one logical change.

🤖 Generated with Claude Code

https://claude.ai/code/session_01AxJrKQ3nzaSxVXcYzZkVu3

---

Generated by Claude Code