ci: Use release-please bootstrap's default config (#187)

Autogenerated the config file and manifest using the cli tool.
I think the main problem was that release-please was not finding the
0.1.0 release (hence the 0.0.0 tag in the manifest).

Adding this tag here should make it pick the correct version for the
next release:

Release-As: 0.2.0

.release-please-manifest.json

@@ -1,3 +1,3 @@
 {
-  ".": "0.1.0"
-}
+  ".": "0.0.0"
+}

release-please-config.json

@@ -1,7 +1,13 @@
 {
-  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json",
-  "include-component-in-tag": false,
-  "packages": ".",
-  "release-type": "python",
-  "bump-minor-pre-major": true
-}
+  "packages": {
+    ".": {
+      "release-type": "python",
+      "changelog-path": "CHANGELOG.md",
+      "bump-minor-pre-major": true,
+      "bump-patch-for-minor-pre-major": false,
+      "draft": false,
+      "prerelease": false
+    }
+  },
+  "$schema": "https://raw.githubusercontent.com/googleapis/release-please/main/schemas/config.json"
+}