**feat: add findSimilar method for entity similarity search**

### Changes:
- Introduced a `findSimilar` method in `src/brainyData.ts`:
  - Enables searching for entities similar to a given entity ID.
  - Supports options such as result limit, noun type filtering, verb inclusion, and search mode (local, remote, or combined).
  - Filters out the original entity in results and returns limited output based on the specified options.
- Updated `brainyDataInterface` in `src/types/brainyDataInterface.ts` to include the new `findSimilar` method definition.

### Purpose:
Added the `findSimilar` method to enhance entity retrieval capabilities by enabling similarity-based searches. This feature improves data exploration and provides a flexible API for building advanced search and recommendation functionalities.

src/types/brainyDataInterface.ts

@@ -44,4 +44,12 @@ export interface BrainyDataInterface<T = unknown> {
    * @returns The ID of the created relationship
    */
   relate(sourceId: string, targetId: string, relationType: string, metadata?: unknown): Promise<string>
+
+  /**
+   * Find entities similar to a given entity ID
+   * @param id ID of the entity to find similar entities for
+   * @param options Additional options
+   * @returns Array of search results with similarity scores
+   */
+  findSimilar(id: string, options?: { limit?: number }): Promise<unknown[]>
 }