packages,plugins: add package documentation

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

plugins/badges/api-report.md

@@ -22,6 +22,4 @@ export const EntityBadgesDialog: ({
   open: boolean;
   onClose?: (() => any) | undefined;
 }) => JSX.Element;
-
-// (No @packageDocumentation comment for this package)
 ```

plugins/badges/src/index.ts

@@ -14,4 +14,10 @@
  * limitations under the License.
  */
 
+/**
+ * A Backstage plugin that generates README badges for your entities
+ *
+ * @packageDocumentation
+ */
+
 export * from './plugin';