Bump mkdocs-llmstxt from 0.5.0 to 0.5.1 in /docs/mkdocs

Bumps [mkdocs-llmstxt](https://github.com/pawamoy/mkdocs-llmstxt) from 0.5.0 to 0.5.1.
- [Release notes](https://github.com/pawamoy/mkdocs-llmstxt/releases)
- [Changelog](https://github.com/pawamoy/mkdocs-llmstxt/blob/main/CHANGELOG.md)
- [Commits](https://github.com/pawamoy/mkdocs-llmstxt/compare/0.5.0...0.5.1)

---
updated-dependencies:
- dependency-name: mkdocs-llmstxt
  dependency-version: 0.5.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

docs/mkdocs/mkdocs.yml

@@ -453,12 +453,8 @@ plugins:
       # package badges (the fetch fails, then reading the missing cache entry
       # raises FileNotFoundError). Readers' browsers are served normally, so
       # leave these badges as external references instead of self-hosting them.
-      # The same goes for img.shields.io, whose version badges time out from
-      # time to time (strict mode turns the failed download into an error) and
-      # would go stale between builds if they were self-hosted anyway.
       assets_exclude:
         - repology.org/*
-        - img.shields.io/*
   - llmstxt:
       markdown_description: >
         JSON for Modern C++ is a C++11 header-only library implementing a JSON

docs/mkdocs/requirements.txt

@@ -7,6 +7,6 @@ mkdocs-material-extensions==1.3.1                   # extensions
 mkdocs-minify-plugin==0.8.0                         # plugin "minify"
 mkdocs-redirects==1.2.3                             # plugin "redirects"
 mkdocs-htmlproofer-plugin==1.6.0                    # plugin "htmlproofer"
-mkdocs-llmstxt==0.5.0                               # plugin "llmstxt"
+mkdocs-llmstxt==0.5.1                               # plugin "llmstxt"
 
 PyYAML==6.0.3                                       # linter