Update github templates

.github/ISSUE_TEMPLATE/SUPPORT_REQUEST.md

@@ -4,6 +4,7 @@ about: I need support for Synapse
 
 ---
 
-# Please ask for support in [**#matrix:matrix.org**](https://matrix.to/#/#matrix:matrix.org)
+Please don't file github issues asking for support.
 
-## Don't file an issue as a support request.
+Instead, please join [`#synapse:matrix.org`](https://matrix.to/#/#synapse:matrix.org)
+(from a matrix.org account if necessary), and ask there.

.github/SUPPORT.md

@@ -1,3 +1,3 @@
-[**#matrix:matrix.org**](https://matrix.to/#/#matrix:matrix.org) is the official support room for Matrix, and can be accessed by any client from https://matrix.org/docs/projects/try-matrix-now.html 
-
-It can also be access via IRC bridge at irc://irc.freenode.net/matrix or on the web here: https://webchat.freenode.net/?channels=matrix
+[**#synapse:matrix.org**](https://matrix.to/#/#synapse:matrix.org) is the official support room for
+Synapse, and can be accessed by any client from https://matrix.org/docs/projects/try-matrix-now.html.
+Please ask for support there, rather than filing github issues.

changelog.d/5552.misc

@@ -0,0 +1 @@
+Update github templates.