Revert "Merge branch '326-htmlproofer' into 'preview'"

This reverts merge request !573

Dockerfile

@@ -6,7 +6,7 @@ SHELL ["/bin/bash", "-c"]
 # Base #
 ########
 
-RUN pip install mkdocs>=1.1.2 mkdocs-material>=7.1.0 mkdocs-htmlproofer-plugin>=0.8.0
+RUN pip install mkdocs>=1.1.2 mkdocs-material>=7.1.0
 
 ##########
 # Linter #
@@ -14,7 +14,7 @@ RUN pip install mkdocs>=1.1.2 mkdocs-material>=7.1.0 mkdocs-htmlproofer-plugin>=
 
 RUN apt-get update && apt-get install -y nodejs npm aspell git
 
-RUN npm install -g markdownlint-cli
+RUN npm install -g markdownlint-cli markdown-link-check
 
 ###########################################
 # prepare git for automatic merging in CI #

doc.zih.tu-dresden.de/mkdocs.yml

@@ -223,4 +223,3 @@ extra:
 plugins:
   - search
   - markdown-caption
-  - htmlproofer