Drop IRC as communication channel, just reference Matrix

by jelmer review by jelmer

README.rst

@@ -54,8 +54,7 @@ like to offer suggestions or feedback, please get in touch with us:
 
   Please mention that you are using Breezy rather than Bazaar.
 
-* Talk to us in irc://irc.oftc.net/breezy or
-  `#breezy:matrix.org <https://matrix.to/#/#breezy:matrix.org>`_.
+* Talk to us in `#breezy:matrix.org <https://matrix.to/#/#breezy:matrix.org>`_.
 
 Our mission is to make a version control tool that developers LOVE to use
 and that casual contributors feel confident with. Please let us know how

doc/developers/HACKING.txt

@@ -7,7 +7,7 @@ It's meant for people interested in developing Breezy, and some parts will
 also be useful to people developing Breezy plugins.
 
 If you have any questions or something seems to be incorrect, unclear or
-missing, please talk to us in ``irc://irc.oftc.net/#breezy``, or write to
+missing, please talk to us on matrix at ``#breezy:matrix.org``, or write to
 the Breezy mailing list.  To propose a correction or addition to this
 document, send a merge request or new text to the mailing list.
 

doc/developers/overview.txt

@@ -4,7 +4,7 @@ Breezy Architectural Overview
 
 This document describes the key classes and concepts within Breezy.  It is
 intended to be useful to people working on the Breezy codebase, or to
-people writing plugins.  People writing plugins may also like to read the 
+people writing plugins.  People writing plugins may also like to read the
 guide to `Integrating with Breezy <integration.html>`_ for some specific recipes.
 
 There's some overlap between this and the `Core Concepts`_ section of the
@@ -14,7 +14,7 @@ internals.  In particular the user guide doesn't go any deeper than
 like inventories, but this guide does.
 
 If you have any questions, or if something seems to be incorrect, unclear
-or missing, please talk to us in ``irc://irc.oftc.net/#breezy``, write to
+or missing, please talk to us on Matrix in ``#breezy:matrix.org``, write to
 the Breezy mailing list, or simply file a bug report.
 
 
@@ -160,7 +160,7 @@ More information
 
 See also:
 
-* `Developer guide to breezy transports <transports.html>`_ 
+* `Developer guide to breezy transports <transports.html>`_
 * API docs for ``breezy.transport.Transport``
 
 Control directory
@@ -207,7 +207,7 @@ WorkingTree
 ===========
 
 A workingtree is a special type of Tree that's associated with a working
-directory on disk, where the user can directly modify the files. 
+directory on disk, where the user can directly modify the files.
 
 Responsibilities:
 
@@ -229,7 +229,7 @@ Branch
 ======
 
 A Branch is a key user concept - its a single line of history that one or
-more people have been committing to. 
+more people have been committing to.
 
 A Branch is responsible for:
 
@@ -254,7 +254,7 @@ and graph relationships between them.  A repository holds a bag of
 revision data that can be pointed to by various branches:
 
 * Maintains storage of various history data at a URL:
-  
+
   * Revisions (Must have a matching inventory)
   * Digital Signatures
   * Inventories for each Revision. (Must have all the file texts available).