Add workflow automation to publish docs

Automates the publication of documentation to github pages when changes are merged to the master
branch. This will keep the github pages in sync with the master barnch and users can use the docs
published to hex.pm for release versions.

Signed-off-by: Winford <[email protected]>

Author: UncleGrumpy

.github/workflows/publish_docs.yml

@@ -0,0 +1,73 @@
+#
+#  Copyright 2025 Winford (Uncle Grumpy) <[email protected]>
+#
+#  SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later
+#
+# This is a workflow for atomvm/atomvm_packbeam to publish documentation to GitHub Pages
+
+name: Publish Docs
+
+on:
+  # Triggers the workflow on tags
+  push:
+   branches:
+      - 'master'
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+jobs:
+  publish:
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+      pull-requests: write
+
+    steps:
+    - name: "Install deps"
+      run: |
+        sudo apt install -y make git
+
+    - uses: actions/checkout@v4
+      with:
+        repository: ${{ vars.GITHUB_REPOSITORY }}
+        fetch-depth: 0
+
+    - uses: erlef/setup-beam@5304e04ea2b355f03681464e683d92e3b2f18451
+      with:
+        otp-version: "27"
+
+    - name: "Build rebar3"
+      run: |
+        cd /tmp
+        git clone https://github.com/erlang/rebar3.git
+        cd rebar3
+        ./bootstrap
+
+    - name: "Build Docs"
+      run: |
+        git checkout -b updates
+        PATH="/tmp/rebar3:${PATH}" make doc
+
+    - name: Commit files
+      if: github.repository == 'atomvm/atomvm_packbeam'
+      run: |
+        git branch --show-current
+        git status
+        git config --local user.email "[email protected]"
+        git config --local user.name "AtomVM Doc Bot"
+        git status
+        git add .
+        git commit -m "Update Documentation ${{ github.ref_name }}"
+
+    - name: Push changes
+      if: github.repository == 'atomvm/atomvm_packbeam'
+      run: |
+        eval `ssh-agent -t 60 -s`
+        echo "${{ secrets.PUBLISH_KEY }}" | ssh-add -
+        mkdir -p ~/.ssh/
+        ssh-keyscan github.com >> ~/.ssh/known_hosts
+        git remote add live_pages "[email protected]:atomvm/atomvm_packbeam.git"
+        git fetch live_pages
+        git diff --quiet live_pages/gh-pages || echo "Pushing updated documentation"
+        git diff --quiet live_pages/gh-pages || git push --set-upstream live_pages updates:gh-pages -f