docs: add release instructions to CONTRIBUTING.md

CONTRIBUTING.md

@@ -22,3 +22,64 @@ sign a new one.
 
 This project follows
 [Google's Open Source Community Guidelines](https://opensource.google/conduct/).
+
+## Releasing (Google team members only)
+
+This section is for Google team members who are responsible for releasing new versions of the test server and SDKs.
+
+### Releasing the `test-server` binary
+
+This process creates a new GitHub release and attaches the compiled binaries.
+
+#### Prerequisites
+
+Make sure you have `goreleaser` installed:
+
+```sh
+go install github.com/goreleaser/goreleaser/v2@latest
+```
+
+#### Steps
+
+1.  Ensure your local `main` branch is up-to-date and clean:
+    ```sh
+    git checkout main && git pull origin main && git clean -xdf
+    ```
+2.  Create and push a new version tag. For example, for version `v0.2.2`:
+    ```sh
+    git tag -a v0.2.2 -m "Release v0.2.2"
+    git push origin v0.2.2
+    ```
+3.  Run GoReleaser:
+    ```sh
+    goreleaser release
+    ```
+4.  Verify that a new release with the updated binaries is available on the project's GitHub Releases page.
+
+### Updating the Go release binary pin in the SDKs
+
+After a new `test-server` binary is released, you need to update the checksums pinned in the SDKs.
+
+1.  Run the `update-sdk-checksums` script with the new version tag. For example:
+    ```sh
+    go run scripts/update-sdk-checksums/main.go v0.2.2
+    ```
+    This updates the pinned checksums (currently only in the TypeScript SDK).
+2.  Commit and push the changes. These changes will be included in the next SDK release.
+
+### Publishing the TypeScript SDK to npm
+
+1.  Ensure your local `main` branch is up-to-date and clean:
+    ```sh
+    git checkout main && git pull origin main && git clean -xdf
+    ```
+2.  Navigate to the TypeScript SDK directory:
+    ```sh
+    cd sdks/typescript
+    ```
+3.  Update the `version` in `package.json` (e.g., using `npm version patch`).
+4.  Install dependencies and build the SDK:
+    ```sh
+    npm ci && npm run build
+    ```
+5.  Publish the new version to npm following internal guidance at go/wombat-dressing-room.