Add ci workflow (#1)

Here is a simple(ish) CI for building the menu.
I am sure it can be improved, but is a great starting point for
developing further.

.github/workflows/build.yml

@@ -0,0 +1,104 @@
+name: build
+
+on:
+  push:
+  pull_request:
+  release:
+    types:
+      - created
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    container:
+      image: ghcr.io/n64-tools/gcc-toolchain-mips64:latest # we use an unofficial container for the moment as git-submodules dont work in the official one!
+      credentials:
+        username: ${{ github.actor }}
+        password: ${{ secrets.github_token }}
+      volumes:
+        - my_docker_volume:/volume_mount
+
+    steps:
+
+      - name: Check for dockerenv file
+        run: (ls /.dockerenv && echo Found dockerenv) || (echo No dockerenv)
+
+      - uses: actions/checkout@v3
+        with:
+          submodules: true
+          fetch-depth: 1 # we only require the last check-in, unless we want to create a changelog.
+
+      - name: Build libdragon
+        run: |
+          cd ./libdragon
+          ./build.sh # release --force-clean
+
+      - name: Build rom
+        run: |
+          # chmod +x build.sh
+          # ./build.sh # release --force-clean
+          mkdir build
+          make -j all
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: N64FlashcartMenu
+          path: |
+            ./build/N64FlashcartMenu.z64
+          if-no-files-found: ignore
+
+  finalize:
+    runs-on: ubuntu-latest
+    needs: build
+
+    steps:
+
+      - name: Setup python
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.11.x'
+
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 1 # we only require the last check-in, unless we want to create a changelog.
+      
+      - name: Download ROM artifact
+        id: download-rom-artifact
+        uses: actions/download-artifact@v3
+        with:
+          name: N64FlashcartMenu
+          path: ./build
+
+      - name: Finalize rom
+        run: |
+          cd ./build
+          python ../tools/finalize.py N64FlashcartMenu.z64
+        continue-on-error: true
+
+      - name: Upload artifact
+        uses: actions/upload-artifact@v3
+        with:
+          name: N64FlashcartMenu
+          path: |
+            ./build/sc64menu.n64
+          if-no-files-found: ignore
+
+      # - name: Get release
+      #   if: github.event_name == 'release' && github.event.action == 'created'
+      #   id: get_release
+      #   uses: bruceadams/get-release@v1.3.2
+      #   env:
+      #     GITHUB_TOKEN: ${{ github.token }}
+
+      # - name: Upload release asset
+      #   if: github.event_name == 'release' && github.event.action == 'created'
+      #   uses: actions/upload-release-asset@v1 # This will start failing soon due to needing node 12!
+      #   env:
+      #     GITHUB_TOKEN: ${{ github.token }}
+      #   with:
+      #     upload_url: ${{ steps.get_release.outputs.upload_url }}
+      #     asset_path: ./build/sc64menu.n64
+      #     asset_name: sc64menu
+      #     asset_content_type: application/zip