Support custom homeservers

[ara4n]

with a ?hs=matrix.org style URL or whatever, as per matrix-org/synapse#1527

[melroy89]

I agree, this should be the basic core feature for years..

[almereyda]

As a side note, supporting custom home servers might also involve supporting custom Element instances.

This idea might also indirectly related to matrix-org/matrix-spec-proposals#2312

[melroy89]

@almereyda That is true, but only valid for desktop Element client I think, for web element it should be rather easy to add support in matrix.to.