fix typos

docs/docs/versions/migrating_memory/index.mdx

@@ -108,7 +108,7 @@ And specific backend implementations of abstractions:
 | `SQLiteEntityStore`       | A specific implementation of `BaseEntityStore` that uses SQLite as the backend.                          |
 | `UpstashRedisEntityStore` | A specific implementation of `BaseEntityStore` that uses Upstash as the backend.                         |
 
-These abstractions have received limited development since their initial release. The is because they generally require significant customization for a specific application to be effective , making
+These abstractions have received limited development since their initial release. This is because they generally require significant customization for a specific application to be effective, making
 them less widely used than the conversation history management abstractions.
 
 For this reason, there are no migration guides for these abstractions. If you're struggling to migrate an application