Workflow to publish on Github

In addition to publishing on `crates.io`, also publish pre-built
binaries on `Github`, using Github actions and cross compilation.
Inspired by: https://github.com/lotabout/skim/blob/master/.github/workflows/publish-github.yml

.cargo/config

@@ -0,0 +1,5 @@
+[target.aarch64-unknown-linux-gnu]
+linker = "aarch64-linux-gnu-gcc"
+
+[target.armv7-unknown-linux-gnueabihf]
+linker = "arm-linux-gnueabihf-gcc"

.github/workflows/release.yml

@@ -9,8 +9,8 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
-  release:
-    name: Publish
+  publish-crate:
+    name: Publish Crate
     runs-on: ubuntu-20.04
     steps:
     - name: Clone
@@ -35,3 +35,110 @@ jobs:
       run: cargo publish
       env:
         CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}
+
+  publish-to-github:
+    name: Publish to Github
+    runs-on: ${{matrix.os}}
+    strategy:
+      matrix:
+        include:
+        - build: linux
+          os: ubuntu-latest
+          rust: stable
+          target: x86_64-unknown-linux-musl
+          cross: false
+        - build: arm-v7
+          os: ubuntu-latest
+          rust: stable
+          target: armv7-unknown-linux-gnueabihf
+          linker: gcc-arm-linux-gnueabihf
+          cross: true
+        - build: aarch64
+          os: ubuntu-latest
+          rust: stable
+          target: aarch64-unknown-linux-gnu
+          linker: gcc-aarch64-linux-gnu
+          cross: true
+        - build: macos
+          os: macos-latest
+          rust: stable
+          target: x86_64-apple-darwin
+          cross: false
+    steps:
+    - name: Checkout repository
+      uses: actions/checkout@v2
+      with:
+        fetch-depth: 1
+
+    - name: Cache
+      uses: actions/cache@v2
+      with:
+        path: |
+          ~/.cargo/registry
+          ~/.cargo/git
+          ~/.rustup
+          target
+        key: ${{ runner.os }}-${{ matrix.rust }}
+
+    - name: Install Linker
+      if: matrix.cross
+      run: |
+        sudo apt update
+        sudo apt install ${{ matrix.linker }}
+
+    - name: Install Rust
+      run: |
+        rustup install ${{ matrix.rust }}
+        rustup target add ${{ matrix.target }}
+        rustup show
+
+    - name: Build
+      run: cargo build --release --target ${{ matrix.target }}
+
+    - name: Package Artifacts
+      run: |
+        src=$(pwd)
+        stage=
+        case $RUNNER_OS in
+            Linux)
+                stage=$(mktemp -d)
+                ;;
+            macOS)
+                stage=$(mktemp -d -t tmp)
+                ;;
+        esac
+
+        cp target/${{ matrix.target }}/release/sysit $stage/
+        cd $stage
+
+        RELEASE_VERSION=${GITHUB_REF#refs/tags/}
+        ASSET_NAME="sysit-$RELEASE_VERSION-${{ matrix.target }}.tar.gz"
+        ASSET_PATH="$src/$ASSET_NAME"
+        CHECKSUM_PATH="$ASSET_PATH.sha256"
+
+        echo "ASSET_PATH=$ASSET_PATH" >> $GITHUB_ENV
+        echo "CHECKSUM_PATH=$CHECKSUM_PATH" >> $GITHUB_ENV
+
+        tar czf $ASSET_PATH *
+
+        cd $src
+
+        case $RUNNER_OS in
+            Linux)
+                sha256sum $ASSET_NAME > $CHECKSUM_PATH
+                ;;
+            macOS)
+                shasum -a 256 $ASSET_NAME > $CHECKSUM_PATH
+                ;;
+        esac
+
+
+    - name: Release
+      uses: softprops/action-gh-release@v1
+      if: startsWith(github.ref, 'refs/tags/')
+      with:
+        files: |
+          ${{ env.ASSET_PATH }}
+          ${{ env.CHECKSUM_PATH }}
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}