Downgrade ruamel.yaml to 0.18.12

Turns out in a recently updated version (0.18.13) the way
mdformat works and formats the yaml in the markdowns
has been changed.

Author: poespas

.github/workflows/lint.yaml

@@ -24,6 +24,6 @@ jobs:
           pip install -r requirements/base.txt
       - name: Check markdown format
         run: mdformat docs/
-      - uses: parkerbxyz/suggest-changes@v1
+      - uses: parkerbxyz/suggest-changes@v2
         with:
           event: 'REQUEST_CHANGES'

requirements/base.txt

@@ -11,6 +11,7 @@ sphinx-notfound-page==1.1.0
 sphinx-sitemap==2.6.0
 sphinx-docsearch
 GitPython==3.1.44
+ruamel.yaml==0.18.12
 
 # hypernode/ requirements
 beautifulsoup4==4.11.1