Replace references to master with main

Signed-off-by: Stephen Finucane <stephen@that.guru>
(cherry picked from commit c3e5c88)
(cherry picked from commit 13f86fb)

Author: stephenfin

README.rst

@@ -6,7 +6,7 @@ Patchwork
    :target: https://pyup.io/repos/github/getpatchwork/patchwork/
    :alt: Requirements Status
 
-.. image:: https://codecov.io/gh/getpatchwork/patchwork/branch/master/graph/badge.svg
+.. image:: https://codecov.io/gh/getpatchwork/patchwork/branch/main/graph/badge.svg
    :target: https://codecov.io/gh/getpatchwork/patchwork
    :alt: Codecov
 

docs/development/releasing.rst

@@ -53,7 +53,7 @@ There is no cadence for releases: they are made available as necessary.
 Supported Versions
 ------------------
 
-Typically all development should occur on ``master``. While we will backport
+Typically all development should occur on ``main``. While we will backport
 bugfixes and security updates, we will not backport any new features. This is
 to ensure stability for users of these versions of Patchwork.
 
@@ -100,12 +100,12 @@ Backporting
 -----------
 
 We will occasionally backport bugfixes and security updates. When backporting a
-patch, said patch should first be merged into ``master``. Once merged, you can
+patch, said patch should first be merged into ``main``. Once merged, you can
 backport by cherry-picking commits, using the ``-x`` flag for posterity:
 
 .. code-block:: shell
 
-   $ git cherry-pick -x <master_commit>
+   $ git cherry-pick -x <main_commit>
 
 There may be some conflicts; resolve these, uncommenting the `Conflicts` line
 when committing::

releasenotes/config.yaml

@@ -1,4 +1,5 @@
 ---
+branch: main
 release_tag_re: 'v\d\.\d\.\d(rc\d+)?'
 pre_release_tag_re: '(?P<pre_release>-rc(?:\d)*)$'
 sections: