Added comment to bookshelf repo

refs bf00d7efc2 (r133860581)

- Making it very clear that the implementation choice was not optimal and was not meant as an "example" implementation. Currently the knex implementation has already taken over in our spike and the bookshelf repository implementation will be removed.

ghost/ghost/src/core/snippets/snippets.repository.bookshelf.ts

@@ -38,6 +38,9 @@ export class SnippetRepositoryBookshelf implements SnippetsRepository {
     }
 
     async getCount(filter?: string | undefined): Promise<number> {
+        // @NOTE: this is an inefficient way to get the count. It's here as a stopgap to get
+        //        the moving pieces working. It should be either replaced with more efficient
+        //        query or the repository would be substituted with a knex implementation.
         const result = await this.models.Snippet.findPage({
             filter: filter
         });