Add release step.

.github/workflows/build.yml

@@ -1,4 +1,4 @@
-name: Rust
+name: Build
 
 on:
   push:

.github/workflows/release.yml

@@ -0,0 +1,60 @@
+name: Build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+
+  build_linux:
+    name: Build Linux
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - run: |
+        sudo apt-get update
+        sudo apt-get install -y libspeechd-dev
+        cargo build --release --verbose
+        mv target linux
+    uses: actions/upload-artifact@v1
+      with:
+        name: linux
+        path: linux
+  build_windows:
+    name: Build Windows
+    runs-on: windows-latest
+    steps:
+    - uses: actions/checkout@v2
+    - run: |
+        choco install -y llvm
+        cargo build --release --verbose
+        move target windows
+    uses: actions/upload-artifact@v1
+      with:
+        name: windows
+        path: windows
+
+  package:
+    name: Package
+    runs-on: ubuntu-latest
+    needs: [build_linux, build_windows]
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/download-artifact@v1
+      with:
+        name: linux
+    - uses: actions/download-artifact@v1
+      with:
+        name: windows
+    - run: |
+        mkdir godot-tts
+        cp godot-tts.gdnlib.release godot-tts/godot-tts.gdnlib
+        mkdir -p godot-tts/target/release
+        cp linux/release/*.so godot-tts/target/release
+        cp windows/release/*.dll godot-tts/target/release
+        cp LICENSE godot-tts
+        cp TTS.gd godot-tts.g* godot-tts
+        cp godot-tts.gdnlib.release godot-tts/godot-tts.gdnlib
+        rm godot-tts/*.release