fixed some typos and other improvements
fixed some typos and other improvements

vector-im/riot-android,vector-im/riot-android,riot-spanish/riot-android,vector-im/vector-android,riot-spanish/riot-android,riot-spanish/riot-android,vector-im/riot-android,vector-im/vector-android,vector-im/riot-android,vector-im/vector-android,vector-im/vector-android,riot-spanish/riot-android,vector-im/riot-android