Update GitHub release job to include plugin artifacts (#19)

Author: buildbreaker

.github/workflows/release.yml

@@ -4,6 +4,8 @@ on:
     tags:
       - v*
   workflow_dispatch: {} # support manual runs
+permissions:
+  contents: write
 jobs:
   library:
     runs-on: ubuntu-latest
@@ -41,3 +43,13 @@ jobs:
           export ORG_GRADLE_PROJECT_signingInMemoryKey=$(gpg --armor --passphrase $GPG_PASSPHRASE --pinentry-mode=loopback --export-secret-keys $GPG_KEY_NAME signing-key | grep -v '\-\-' | grep -v '^=.' | tr -d '\n')
           shred signing-key
           make release
+      - name: sha256
+        run: sha256sum ./protoc-gen-connect-kotlin/build/libs/protoc-gen-connect-kotlin.jar >> sha256.txt
+      - name: Publish GitHub artifacts
+        uses: softprops/action-gh-release@v1
+        with:
+          generate_release_notes: true
+          append_body: true
+          files: |
+            ./protoc-gen-connect-kotlin/build/libs/protoc-gen-connect-kotlin.jar
+            sha256.txt