Bump markdown-include from 0.6.0 to 0.8.0 in /docs/user (#251)

Bumps [markdown-include](https://github.com/cmacmackin/markdown-include) from 0.6.0 to 0.8.0.
- [Release notes](https://github.com/cmacmackin/markdown-include/releases)
- [Commits](cmacmackin/markdown-include@v0.6.0...v0.8.0)

---
updated-dependencies:
- dependency-name: markdown-include
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

docs/user/requirements.txt

@@ -2,7 +2,7 @@ mkdocs==1.4.0
 mkdocs-material==8.5.6
 mkdocstrings[python]==0.20.0
 mkdocstrings-python==0.7.1
-markdown-include==0.6.0
+markdown-include==0.8.0
 mkdocs-gen-files==0.4.0
 mkdocs-exclude==1.0.2
 mkdocs-awesome-pages-plugin==2.8.0