Added Xcode workspaces build instructions
Added Xcode workspaces build instructions

vector-im/riot-ios,matrix-org/matrix-ios-console,vector-im/riot-ios,vector-im/vector-ios,vector-im/riot-ios,vector-im/riot-ios,vector-im/riot-ios,vector-im/vector-ios,vector-im/vector-ios,vector-im/riot-ios,matrix-org/matrix-ios-console