[hitori/rename-to-main] docs: Document renaming of master branch to main

[Philip Withnall <pwithnall src gnome org>]

commit 9a809bf820cbda54f2479a163d8645171ac46dfd
Author: Philip Withnall <pwithnall endlessos org>
Date:   Mon Jul 5 15:40:21 2021 +0100

    docs: Document renaming of master branch to main
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>

 README.md | 13 +++++++++++++
 1 file changed, 13 insertions(+)
---
diff --git a/README.md b/README.md
index e5f7bd9..febe0fb 100644
--- a/README.md
+++ b/README.md
@@ -48,3 +48,16 @@ Contact
 Philip Withnall <philip tecnocode co uk>
 
 https://wiki.gnome.org/Apps/Hitori
+
+## Default branch renamed to `main`
+
+The default development branch of Hitori has been renamed to `main`. To update
+your local checkout, use:
+```sh
+git checkout master
+git branch -m master main
+git fetch
+git branch --unset-upstream
+git branch -u origin/main
+git symbolic-ref refs/remotes/origin/HEAD refs/remotes/origin/main
+```