RSS bot should have a profile image

[MarkWieczorek]

The RSS bot does not have a profile image. Because of this, every post made by the RSS bot uses the ugly default, which is "R" in a circle.

I would suggest adding a profile image in order to improve how Matrix/Element looks to new (and old) users. The easiest thing to do would be to just add an "RSS icon". But maybe someone could come up with something better!