Support for Room Tags

The matrix-react-sdk supports arbitrary room Tags through the matrix-tag-manager standalone app so that you are not limited to just People and Rooms as headings to organize the rooms. This feature is requested for matrix-ios and matrix-android

No file, test, or entry point is named. Start by reading how matrix-react-sdk and the matrix-tag-manager standalone app represent arbitrary room Tags, then compare that with the matrix-ios-sdk structure. Done means matrix-ios-sdk supports arbitrary room Tags rather than only People and Rooms, with corresponding behavior for the requested iOS and Android clients.

Written by the indexing model from the issue text.