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>

lib/python/qmk/cli/generate/__init__.py

@@ -1 +1,2 @@
 from . import api
+from . import docs

lib/python/qmk/cli/generate/docs.py

@@ -0,0 +1,37 @@
+"""Build QMK documentation locally
+"""
+import shutil
+import subprocess
+from pathlib import Path
+
+from milc import cli
+
+DOCS_PATH = Path('docs/')
+BUILD_PATH = Path('.build/docs/')
+
+
+@cli.subcommand('Build QMK documentation.', hidden=False if cli.config.user.developer else True)
+def generate_docs(cli):
+    """Invoke the docs generation process
+
+    TODO(unclaimed):
+        * [ ] Add a real build step... something static docs
+    """
+
+    if BUILD_PATH.exists():
+        shutil.rmtree(BUILD_PATH)
+
+    shutil.copytree(DOCS_PATH, BUILD_PATH)
+
+    # When not verbose we want to hide all output
+    args = {'check': True}
+    if not cli.args.verbose:
+        args.update({'stdout': subprocess.DEVNULL, 'stderr': subprocess.STDOUT})
+
+    cli.log.info('Generating internal docs...')
+
+    # Generate internal docs
+    subprocess.run(['doxygen', 'Doxyfile'], **args)
+    subprocess.run(['moxygen', '-q', '-a', '-g', '-o', BUILD_PATH / 'internals_%s.md', 'doxygen/xml'], **args)
+
+    cli.log.info('Successfully generated internal docs to %s.', BUILD_PATH)