feat: introduce github action to publish to crates (#32)

Ref: #30

.github/workflows/crates.yml

@@ -0,0 +1,21 @@
+name: Publish to Crates
+on:
+    release:
+        types: [created]
+    workflow_dispatch:
+
+jobs:
+    build:
+        runs-on: ubuntu-latest
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v2
+            - name: Install stable toolchain
+              uses: actions-rs/toolchain@v1
+              with:
+                  profile: minimal
+                  toolchain: stable
+                  override: true
+            - run: cargo publish --token ${CRATES_TOKEN}
+              env:
+                  CRATES_TOKEN: ${{ secrets.CRATES_GBPROD_GITCOMMIT }}

.github/workflows/npm.yml

@@ -2,6 +2,8 @@ name: Publish to NPM
 on:
     release:
         types: [created]
+    workflow_dispatch:
+
 jobs:
     build:
         runs-on: ubuntu-latest