chore(ci): set up release-please (googleapis#1616)

* chore(ci): set up release-please

* move config files to proper location

* include readmes in version bump

Author: diegomarquezp

.release-please-manifest.json

@@ -0,0 +1,3 @@
+{
+  ".": "1.30.1"
+}

release-please-config.json

@@ -0,0 +1,21 @@
+{
+  "release-type": "java-yoshi-mono-repo",
+  "separate-pull-requests": false,
+  "include-component-in-tag": false,
+  "group-pull-request-title-pattern": "chore(${branch}): release ${version}",
+  "packages": {
+    ".": {
+      "changelog-path": "CHANGELOG.md",
+      "release-type": "java-yoshi",
+      "bump-minor-pre-major": false,
+      "bump-patch-for-minor-pre-major": false,
+      "draft": false,
+      "prerelease": false,
+      "extra-files": [
+        "README.md",
+        "bom/README.md"
+      ]
+    }
+  },
+  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json"
+}