Merge workflows. (#234)

- Merge all the workflows into one file.
- Produce Windows and MacOS artifact.

.github/workflows/release.yaml

@@ -1,39 +0,0 @@
-name: Release
-
-on:
-  create:
-    tags:
-      -v*
-
-jobs:
-  build:
-    name: Release 
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v2
-        with:
-          fetch-depth: 0
-
-      - uses: seanmiddleditch/gha-setup-ninja@master
-
-      - name: Build
-        run: >
-          mkdir build;
-          cd build;
-          cmake ..
-          -DCMAKE_CXX_COMPILER=clang++
-          -DFTXUI_BUILD_DOCS=OFF
-          -DFTXUI_BUILD_EXAMPLES=OFF
-          -DFTXUI_BUILD_TESTS=OFF
-          -DFTXUI_BUILD_TESTS_FUZZER=OFF
-          -DFTXUI_ENABLE_INSTALL=ON;
-          cmake --build . --config Release;
-          make package;
-
-      - name: Upload 
-        uses: softprops/action-gh-release@v1
-        with:
-          files: build/ftxui-*
-          draft: true
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}