packages,plugins: add package documentation

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

plugins/techdocs/api-report.md

@@ -390,6 +390,4 @@ export class TechDocsStorageClient implements TechDocsStorageApi {
 // src/home/components/EntityListDocsTable.d.ts:11:5 - (ae-forgotten-export) The symbol "columnFactories" needs to be exported by the entry point index.d.ts
 // src/home/components/EntityListDocsTable.d.ts:12:5 - (ae-forgotten-export) The symbol "actionFactories" needs to be exported by the entry point index.d.ts
 // src/plugin.d.ts:29:5 - (ae-forgotten-export) The symbol "TabsConfig" needs to be exported by the entry point index.d.ts
-
-// (No @packageDocumentation comment for this package)
 ```

plugins/techdocs/src/index.ts

@@ -14,6 +14,12 @@
  * limitations under the License.
  */
 
+/**
+ * The Backstage plugin that renders technical documentation for your components
+ *
+ * @packageDocumentation
+ */
+
 export * from './api';
 export { techdocsApiRef, techdocsStorageApiRef } from './api';
 export type { TechDocsApi, TechDocsStorageApi } from './api';