ci: Setup automatic crate publishing

This is the tested pipeline for all the NEAR crates, which simplified the release process to a no-brainer - just merge the automatically generated release PR when you are ready, and release-plz will take care of everything else

.github/workflows/release-plz.yml

@@ -0,0 +1,29 @@
+name: Release-plz
+
+permissions:
+  pull-requests: write
+  contents: write
+
+on:
+  push:
+    branches:
+      - master
+
+jobs:
+  release-plz:
+    name: Release-plz
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+          token: ${{ secrets.RELEASE_PLZ_GITHUB_TOKEN }}
+      - name: Install Rust toolchain
+        uses: dtolnay/rust-toolchain@stable
+      - name: Run release-plz
+        uses: MarcoIeni/release-plz-action@v0.5
+        env:
+          # https://marcoieni.github.io/release-plz/github-action.html#triggering-further-workflow-runs
+          GITHUB_TOKEN: ${{ secrets.RELEASE_PLZ_GITHUB_TOKEN }}
+          CARGO_REGISTRY_TOKEN: ${{ secrets.CARGO_REGISTRY_TOKEN }}