Add OSM-CA Matrix channel

[Undearius]

No description provided.

[haansn08]

There seem to be only two members in this room. Are you sure this is an active community?

[Undearius]

There are only 2 members that have joined the space but there are (slightly) more that have joined the rooms within the space.

The sign-up page for the Slack channel is non-functional and no longer maintained, and has since been removed from this index. The users in the Slack channel we're interested in, and unaware of, the Matrix channel.

The Matrix channel is a lot easier to maintain and more in line with the philosophy of OSM, I figured it would be valuable to have on this list so that others are aware of it, as dead as it may be.

[bhousel]

Thanks 👍