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

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+#
+#  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:
+  build:
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+
+    steps:
+    - name: "Install deps"
+      run: |
+        sudo apt install -y make git
+
+    - uses: erlef/setup-beam@v1
+      with:
+        otp-version: "28"
+
+    - name: "Build rebar3"
+      run: |
+        cd /tmp
+        git clone https://github.com/erlang/rebar3.git
+        cd rebar3
+        ./bootstrap
+
+    - name: "Checkout code"
+      uses: actions/checkout@v4
+      with:
+        repository: ${{ vars.GITHUB_REPOSITORY }}
+        fetch-depth: 0
+
+    - name: "Setup Pages"
+      uses: actions/configure-pages@v5
+
+    - name: "Build Docs"
+      run: |
+        PATH="/tmp/rebar3:${PATH}" make doc
+
+    - name: Upload docs artifact
+      uses: actions/upload-artifact@v4
+      with:
+        name: github-pages
+        path: ./docs
+        if-no-files-found: error
+
+  deploy:
+    # Add a dependency to the build job
+    needs: build
+
+    # Grant GITHUB_TOKEN the permissions required to make a Pages deployment
+    permissions:
+      pages: write      # to deploy to Pages
+      id-token: write   # to verify the deployment originates from an appropriate source
+
+    # Deploy to the github-pages environment
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+
+    # Specify runner + deployment step
+    runs-on: ubuntu-latest
+    steps:
+      - name: Deploy to GitHub Pages
+        if: ${{ github.repository == 'atomvm/atomvm_packbeam' }}
+        id: deployment
+        uses: actions/deploy-pages@v4