Added an html linter. It doesn't produce any errors. Either the code is flawless, or the linting doesn't actually happen.

docker-compose.yml

@@ -8,5 +8,9 @@ services:
         volumes:
             - ./themes/patek/assets/js:/src:ro
             - ./linting/js/eslintrc.yml:/eslintrc.yml
-
+    xo-html-lint:
+        image: patek-devs/eslint-xo
+        command: \*.html --plugin=html --extension=html
+        volumes: 
+            - ./:/src:ro
 

linting/js/Dockerfile

@@ -12,6 +12,8 @@ RUN npm install npm@5.3 && \
 
 RUN npm install -g xo@0.24.0
 
+RUN npm install -g eslint-plugin-html@6.0.0
+
 # Cleanup
 RUN rm -fr /root/.npm /node_modules