Add docs build CI

.gitea/workflows/build.yaml

@@ -0,0 +1,50 @@
+# Based on https://github.com/riscv/riscv-isa-manual/blob/main/.github/workflows/isa-build.yml
+name: Central(Architecture) Docs Build
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+    types: [opened, synchronize]
+
+env:
+  DOCKER_IMG: docker-asciidoctor-wavedrom
+
+jobs:
+  build:
+    name: Build Documentation
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+      
+      - name: Set short SHA
+        run: echo "SHORT_SHA=$(echo ${GITEA_SHA::7})" >> $GITEA_ENV
+        
+      - name: Get current date
+        run: echo "CURRENT_DATE=$(date +'%Y-%m-%d')" >> $GITEA_ENV
+
+      - name: Login to Gitea Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ vars.CONTAINER_REGISTRY_URL }}
+          username: ${{ vars.CONTAINER_REGISTRY_USERNAME }}
+          password: ${{ secrets.CONTAINER_REGISTRY_TOKEN }}
+
+      - name: Pull Container
+        id: pull_container_image
+        run: docker pull ${{ vars.CONTAINER_REGISTRY_URL }}/${{ gitea.repository_owner }}/${{ env.DOCKER_IMG }}:latest
+
+      - name: Build Files
+        id: build_files
+        if: steps.pull_container_image.outcome == 'success'
+        run: make -j$(nproc)
+
+      - name: Upload central-execution-engine-spec.pdf
+        if: steps.build_files.outcome == 'success'
+        uses: actions/upload-artifact@v4
+        with:
+          name: central-execution-engine-spec-${{ env.SHORT_SHA }}.pdf
+          path: ${{ gitea.workspace }}/build/central-execution-engine-spec.pdf
+          retention-days: 7