chore: Add API Reference

Signed-off-by: Adam Harvey <adaharve@cisco.com>

plugins/dynatrace/api-report.md

@@ -16,6 +16,4 @@ export const DynatraceTab: () => JSX.Element;
 
 // @public
 export const isDynatraceAvailable: (entity: Entity) => boolean;
-
-// (No @packageDocumentation comment for this package)
 ```

plugins/dynatrace/src/index.ts

@@ -14,4 +14,10 @@
  * limitations under the License.
  */
 
+/**
+ * A Backstage plugin that integrates towards Dynatrace.
+ *
+ * @packageDocumentation
+ */
+
 export { dynatracePlugin, DynatraceTab, isDynatraceAvailable } from './plugin';