Bump kramdown from 2.4.0 to 2.5.0

Bumps [kramdown](https://github.com/gettalong/kramdown) from 2.4.0 to 2.5.0.
- [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-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -162,8 +162,8 @@ GEM
       thor (>= 0.14, < 2.0)
     jwt (2.9.3)
       base64
-    kramdown (2.4.0)
-      rexml
+    kramdown (2.5.0)
+      rexml (>= 3.3.6)
     launchy (3.0.0)
       addressable (~> 2.8)
       childprocess (~> 5.0)
@@ -275,7 +275,7 @@ GEM
       psych (>= 4.0.0)
     reline (0.5.0)
       io-console (~> 0.5)
-    rexml (3.3.8)
+    rexml (3.3.9)
     rspec (3.13.0)
       rspec-core (~> 3.13.0)
       rspec-expectations (~> 3.13.0)