Updated default branch to main

Signed-off-by: Miquel Sabaté Solà <msabate@suse.com>

Author: mssola

.github/workflows/ci.yml

@@ -2,9 +2,9 @@ name: CI
 
 on:
   push:
-    branches: [master]
+    branches: [main]
   pull_request:
-    branches: [master]
+    branches: [main]
 
 jobs:
   build:

CONTRIBUTING.md

@@ -25,7 +25,7 @@ code. Thus, in order to report issues you can do it on its [issue
 tracker](https://github.com/mssola/useragent/issues). A couple of notes on
 reports:
 
-- Check that the issue has not already been reported or fixed in `master`.
+- Check that the issue has not already been reported or fixed in `main`.
 - Try to be concise and precise in your description of the problem.
 - Provide a step by step guide on how to reproduce this problem.
 - Provide the version you are using (the commit SHA, if possible).