Adding github workflow

Adding github workflow

.github/workflows/build-pdf.yml

@@ -0,0 +1,72 @@
+name: Create Specification Document
+
+# The workflow is triggered by pull request, push to main, and manual dispatch.
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'Release version, e.g. X.Y.Z:'
+        required: true
+        type: string
+      revision_mark: 
+          description: 'Set revision mark as Draft, Release or Stable:'
+          required: true
+          type: string
+          default: 'Draft'
+      prerelease:
+        description: 'Tag as a pre-release?'
+        required: false
+        type: boolean
+        default: true
+      draft:
+        description: 'Create release as a draft?'
+        required: false
+        type: boolean
+        default: false
+  pull_request:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    # Step 1: Checkout the repository
+    - name: Checkout repository
+      uses: actions/checkout@v3
+      with:
+        submodules: 'recursive'
+
+    # Step 2: Pull the latest RISC-V Docs container image
+    - name: Pull Container
+      run: docker pull riscvintl/riscv-docs-base-container-image:latest
+
+    # Step 3: Build Files
+    - name: Build Files
+      run: make
+      env:
+        VERSION: v${{ github.event.inputs.version }}
+        REVMARK: ${{ github.event.inputs.revision_mark }}
+
+    # Step 4: Upload the built PDF files as a single artifact
+    - name: Upload Build Artifacts
+      uses: actions/upload-artifact@v3
+      with:
+        path: ${{ github.workspace }}/*.pdf
+        retention-days: 30
+
+    # Create Release
+    - name: Create Release
+      uses: softprops/action-gh-release@v1
+      with:
+        files: ${{ github.workspace }}/*.pdf
+        tag_name: v${{ github.event.inputs.version }}
+        name: Release ${{ github.event.inputs.version }}
+        draft: ${{ github.event.inputs.draft }}
+        prerelease: ${{ github.event.inputs.prerelease }}
+      env:
+        GITHUB_TOKEN: ${{ secrets.GHTOKEN }}
+      if: github.event_name == 'workflow_dispatch' 
+      # This condition ensures this step only runs for workflow_dispatch events.