Fixes https://github.com/turt2live/matrix-media-repo/issues/49

Fixes https://github.com/turt2live/matrix-media-repo/issues/215

Fixes https://github.com/turt2live/matrix-media-repo/issues/214

The script appears to work, just needed some touchups.

Fixes https://github.com/turt2live/matrix-media-repo/issues/93

Fixes https://github.com/turt2live/matrix-media-repo/issues/145

This seems like it was overlooked when writing the documentation.

and include instructions on how to build this on alpine

This is done over http to ensure that synapse is left with a backup of the media repository. 

Adds #4