Remove vector-electron-desktop from README
Remove vector-electron-desktop from README

The repo (https://github.com/iskrisis/vector-electron-desktop) very clearly states not to use it anymore.
vector-im/vector-web,vector-im/riot-web,vector-im/riot-web,vector-im/riot-web,vector-im/vector-web,vector-im/vector-web,vector-im/riot-web,vector-im/vector-web,vector-im/vector-web,vector-im/riot-web,vector-im/riot-web