chore: add more github workflows (#9)

.github/dependabot.yml

@@ -0,0 +1,8 @@
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every weekday
+      interval: "daily"

.github/release-drafter.yml

@@ -0,0 +1,4 @@
+template: |
+  ## What’s Changed
+
+  $CHANGES

.github/workflows/gem-push.yml

@@ -1,8 +1,6 @@
 name: Push to Rubygems
 
 on:
-  push:
-    branches: [master]
   pull_request:
     branches: [master]
 

.github/workflows/release-drafter.yml

@@ -0,0 +1,32 @@
+name: Release Drafter
+
+on:
+  push:
+    # branches to consider in the event; optional, defaults to all
+    branches:
+      - master
+  # pull_request event is required only for autolabeler
+  pull_request:
+    # Only following types are handled by the action, but one can default to all as well
+    types: [opened, reopened, synchronize]
+  # pull_request_target event is required for autolabeler to support PRs from forks
+  # pull_request_target:
+  #   types: [opened, reopened, synchronize]
+
+jobs:
+  update_release_draft:
+    runs-on: ubuntu-latest
+    steps:
+      # (Optional) GitHub Enterprise requires GHE_HOST variable set
+      #- name: Set GHE_HOST
+      #  run: |
+      #    echo "GHE_HOST=${GITHUB_SERVER_URL##https:\/\/}" >> $GITHUB_ENV
+
+      # Drafts your next Release notes as Pull Requests are merged into "master"
+      - uses: release-drafter/release-drafter@v5
+        # (Optional) specify config name to use, relative to .github/. Default: release-drafter.yml
+        # with:
+        #   config-name: my-config.yml
+        #   disable-autolabeler: true
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}