CI: Add docs build and deploy workflow (#7448)

* Add docs build and deploy workflow

* Remove old travis docs workflow

* update to cli command

* Tidy up for review

* formatting

* Update to pass style checks

* Update lib/python/qmk/cli/docs.py

Co-Authored-By: skullydazed <skullydazed@users.noreply.github.com>

* Review comments - build->generate, use of verbose

* Add docs

* Update to match recent actions

* Run within base_container

* Convert cli to generate-docs

* Convert cli to generate-docs - restore old file

* Convert cli to generate-docs

* Update docs

Co-authored-by: skullydazed <skullydazed@users.noreply.github.com>

.github/workflows/docs.yml

@@ -0,0 +1,43 @@
+name: Generate Docs
+
+on:
+  push:
+    branches:
+    - master
+    paths:
+    - 'tmk_core/**'
+    - 'quantum/**'
+    - 'platforms/**'
+    - 'docs/**'
+    - '.github/workflows/docs.yml'
+
+jobs:
+  generate:
+    runs-on: ubuntu-latest
+    container: qmkfm/base_container
+
+    # protect against those who develop with their fork on master
+    if: github.repository == 'qmk/qmk_firmware'
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 1
+
+    - name: Install dependencies
+      run: |
+        apt-get update && apt-get install -y rsync nodejs npm doxygen
+        npm install -g moxygen
+
+    - name: Build docs
+      run: |
+        qmk --verbose generate-docs
+
+    - name: Deploy
+      uses: JamesIves/github-pages-deploy-action@3.7.1
+      with:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        BASE_BRANCH: master
+        BRANCH: gh-pages
+        FOLDER: .build/docs
+        GIT_CONFIG_EMAIL: hello@qmk.fm