Bump kramdown from 2.5.0 to 2.5.1 (#170)

Bumps [kramdown](https://github.com/gettalong/kramdown) from 2.5.0 to 2.5.1.
- [Release notes](https://github.com/gettalong/kramdown/releases)
- [Changelog](https://github.com/gettalong/kramdown/blob/master/doc/news.page)
- [Commits](https://github.com/gettalong/kramdown/commits)

---
updated-dependencies:
- dependency-name: kramdown
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -46,8 +46,8 @@ GEM
       concurrent-ruby (~> 1.1)
       sorted_set (~> 1.0)
     json_schema (0.21.0)
-    kramdown (2.5.0)
-      rexml (>= 3.3.6)
+    kramdown (2.5.1)
+      rexml (>= 3.3.9)
     listen (3.7.1)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)