[gnome-builder] Add Matrix links to README.md and CONTRIBUTING.md

[Christian Hergert <chergert src gnome org>]

commit 6129e3abeac4aa5bccb766c268d0436dc94e246b
Author: Newbyte <newbie13xd gmail com>
Date:   Tue Mar 9 16:37:48 2021 +0100

    Add Matrix links to README.md and CONTRIBUTING.md

 CONTRIBUTING.md | 6 ++++--
 README.md       | 4 ++++
 2 files changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 05fef9be3..546143bb4 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -21,10 +21,12 @@ and we'd be happy to review your patch and help you get it merged.
 ## Asking for Help
 
 You can often find Builder contributors on our IRC channel at
-[irc://irc.gimp.net/#gnome-builder](irc://irc.gimp.net/#gnome-builder).
+[irc://irc.gimp.net/#gnome-builder](irc://irc.gimp.net/#gnome-builder) or the
+Matrix channel at [#gnome-builder:gnome.org](https://matrix.to/#/!owVIjvsVrBaEdelYem:matrix.org).
 If you have any questions, we'd be happy to help you.
 
-If you'd like to start on a new plugin or feature, stop by our IRC channel and we'd be happy get you 
oriented.
+If you'd like to start on a new plugin or feature, stop by our IRC/Matrix channel and we'd be happy get you 
oriented.
+The IRC and Matrix channels are bridged so you will be part of the same conversation regardless of which you 
join.
 
 ## Portability
 
diff --git a/README.md b/README.md
index ea6f0ee9f..32aead7fc 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,10 @@ Develop software for GNOME
  * [Browse source code in Git version control](https://gitlab.gnome.org/GNOME/gnome-builder)
  * [Learn more about Builder](https://wiki.gnome.org/Apps/Builder)
  * [Chat with the developers](irc://irc.gnome.org/#gnome-builder) in #gnome-builder on irc.gnome.org
+ or [#gnome-builder:gnome.org](https://matrix.to/#/!owVIjvsVrBaEdelYem:matrix.org) on GNOME's Matrix.
+
+The IRC and Matrix channels are bridged to each other, which means that messages sent on one also come 
through on
+the other. In other words, you will be part of the same conversation regardless of which you join.
 
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