build: add auto-approve to Node libraries (#1100)

* build: add auto-approve to Node libraries

Co-authored-by: Benjamin E. Coe <bencoe@google.com>

Author: sofisl

synthtool/gcp/templates/node_library/.github/CODEOWNERS

@@ -11,3 +11,6 @@
 {%- else %}
 *     @googleapis/yoshi-nodejs
 {%- endif %}
+
+# The github automation team is the default owner for the auto-approve file.
+.github/auto-approve.yml @googleapis/github-automation

synthtool/gcp/templates/node_library/.github/auto-approve.yml

@@ -0,0 +1,7 @@
+rules:
+- author: "release-please[bot]"
+  title: "^chore: release"
+  changedFiles:
+  - "package\\.json$"
+  - "CHANGELOG\\.md$"
+  maxFiles: 3