Added supported plugins to Docker image (#1458)

.dockerignore

@@ -0,0 +1,5 @@
+.git
+.github
+docs
+node_modules
+src

Dockerfile

@@ -18,7 +18,7 @@
 # FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 # IN THE SOFTWARE.
 
-FROM python:3.6.8-alpine3.9
+FROM python:3.8.1-alpine3.11
 
 # Set build directory
 WORKDIR /tmp
@@ -38,7 +38,10 @@ RUN \
     git-fast-import \
     openssh \
   && python setup.py install \
-  && rm -rf /tmp/*
+  && rm -rf /tmp/* \
+  && pip install --no-cache-dir \
+    'mkdocs-minify-plugin>=0.2' \
+    'mkdocs-git-revision-date-localized-plugin'
 
 # Set working directory
 WORKDIR /docs

requirements.txt

@@ -20,7 +20,6 @@
 
 # Direct dependencies
 mkdocs>=1.0
-mkdocs-minify-plugin>=0.2
 Pygments>=2.4
 markdown>=3.2
 pymdown-extensions>=6.3