packages,plugins: add package documentation

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

plugins/todo/api-report.md

@@ -86,6 +86,4 @@ export type TodoListResult = {
 
 // @public
 export const todoPlugin: BackstagePlugin<{}, {}>;
-
-// (No @packageDocumentation comment for this package)
 ```

plugins/todo/src/index.ts

@@ -14,6 +14,12 @@
  * limitations under the License.
  */
 
+/**
+ * A Backstage plugin that lets you browse TODO comments in your source code
+ *
+ * @packageDocumentation
+ */
+
 export { todoApiRef, TodoClient } from './api';
 export type {
   TodoApi,