Update Dockerfile to use specific package versions

Author: csharpfritz

docs/Dockerfile

@@ -1,15 +1,14 @@
 FROM squidfunk/mkdocs-material:5.5.0
 
-RUN \
-  apk add --no-cache \
-    git \
-    git-fast-import \
-    openssh \
+RUN apk add --no-cache \
+      git \
+      git-fast-import \
+      openssh \
   && apk add --no-cache --virtual .build gcc musl-dev \
   && pip install --no-cache-dir \
-    'markdown-include' \
-    'mike' \
-    'mkdocs-exclude' \
-    'mkdocs-macros-plugin' \
+      'markdown-include==0.5.1' \
+      'mike==1.1.2' \
+      'mkdocs-exclude==1.0.2' \
+      'mkdocs-macros-plugin==0.5.12' \
   && apk del .build gcc musl-dev \
   && rm -rf /tmp/*