Add Github Action to build release firmware on tag (#20)

.github/workflows/release.yml

@@ -0,0 +1,40 @@
+name: Compile Release
+on:
+  push:
+    tags:
+      - '*'
+
+jobs:
+  build-release:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v6
+        with:
+          submodules: recursive
+      - uses: actions/cache@v5
+        with:
+          path: |
+            ~/.cache/pip
+            ~/.platformio/.cache
+          key: ${{ runner.os }}-pio
+      - uses: actions/setup-python@v6
+        with:
+          python-version: '3.14'
+
+      - name: Install PlatformIO Core
+        run: pip install --upgrade platformio
+
+      - name: Build CrossPoint
+        run: pio run -e gh_release
+
+      - name: Upload Artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: CrossPoint-${{ github.ref_name }}
+          path: |
+            .pio/build/gh_release/bootloader.bin
+            .pio/build/gh_release/firmware.bin
+            .pio/build/gh_release/firmware.elf
+            .pio/build/gh_release/firmware.map
+            .pio/build/gh_release/partitions.bin