Docs: Fix broken links and references in docs

Also add to the CI a problem matcher to better report issues

Signed-off-by: Brennan Ashton <bashton@brennanashton.com>

.github/workflows/doc.yml

@@ -16,7 +16,7 @@ on:
   push:
 
 jobs:
-  docs:
+  build-html:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v1
@@ -28,6 +28,7 @@ jobs:
         cd Documentation/
         pip3 install pipenv
         pipenv lock -r > requirements.txt
+    - uses: ammaraskar/sphinx-problem-matcher@master
     - uses: ammaraskar/sphinx-action@master
       with:
         docs-folder: "Documentation/"
@@ -35,3 +36,17 @@ jobs:
       with:
         name: sphinx-docs
         path: Documentation/_build/html/
+  linkcheck:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - uses: actions/setup-python@v2
+      with:
+        python-version: '3.8'
+    - uses: ammaraskar/sphinx-problem-matcher@master
+    - name: Run linkcheck
+      run: |
+        cd Documentation/
+        pip3 install pipenv
+        pipenv install
+        pipenv run make linkcheck