Rename master branch to main

Author: WhyNotHugo

README.rst

@@ -6,8 +6,8 @@ vdirsyncer
   :target: https://builds.sr.ht/~whynothugo/vdirsyncer
   :alt: CI status
 
-.. image:: https://codecov.io/github/pimutils/vdirsyncer/coverage.svg?branch=master
-  :target: https://codecov.io/github/pimutils/vdirsyncer?branch=master
+.. image:: https://codecov.io/github/pimutils/vdirsyncer/coverage.svg?branch=main
+  :target: https://codecov.io/github/pimutils/vdirsyncer?branch=main
   :alt: Codecov coverage report
 
 .. image:: https://readthedocs.org/projects/vdirsyncer/badge/
@@ -23,7 +23,7 @@ vdirsyncer
   :alt: Debian packages
 
 .. image:: https://img.shields.io/pypi/l/vdirsyncer.svg
-  :target: https://github.com/pimutils/vdirsyncer/blob/master/LICENCE
+  :target: https://github.com/pimutils/vdirsyncer/blob/main/LICENCE
   :alt: licence: BSD
 
 - `Documentation <https://vdirsyncer.pimutils.org/en/stable/>`_

docs/tutorial.rst

@@ -16,7 +16,7 @@ Configuration
 .. note::
 
     - The `config.example from the repository
-      <https://github.com/pimutils/vdirsyncer/blob/master/config.example>`_
+      <https://github.com/pimutils/vdirsyncer/blob/main/config.example>`_
       contains a very terse version of this.
 
     - In this example we set up contacts synchronization, but calendar sync

docs/tutorials/systemd-timer.rst

@@ -13,8 +13,8 @@ minutes).
     unit files, you'll need to download vdirsyncer.service_ and vdirsyncer.timer_
     into either ``/etc/systemd/user/`` or ``~/.local/share/systemd/user``.
 
-.. _vdirsyncer.service: https://raw.githubusercontent.com/pimutils/vdirsyncer/master/contrib/vdirsyncer.service
-.. _vdirsyncer.timer: https://raw.githubusercontent.com/pimutils/vdirsyncer/master/contrib/vdirsyncer.timer
+.. _vdirsyncer.service: https://raw.githubusercontent.com/pimutils/vdirsyncer/main/contrib/vdirsyncer.service
+.. _vdirsyncer.timer: https://raw.githubusercontent.com/pimutils/vdirsyncer/main/contrib/vdirsyncer.timer
 
 Activation
 ----------