README.md in annoy-rb-0.2.2 vs README.md in annoy-rb-0.2.3

- old
+ new

@@ -1,10 +1,10 @@
 # Annoy.rb
 
 [![Build Status](https://github.com/yoshoku/annoy.rb/workflows/build/badge.svg)](https://github.com/yoshoku/annoy.rb/actions?query=workflow%3Abuild)
 [![Gem Version](https://badge.fury.io/rb/annoy-rb.svg)](https://badge.fury.io/rb/annoy-rb)
-[![License](https://img.shields.io/badge/License-Apache%202.0-yellowgreen.svg)](https://github.com/yoshoku/annoy.rb/blob/master/LICENSE.txt)
+[![License](https://img.shields.io/badge/License-Apache%202.0-yellowgreen.svg)](https://github.com/yoshoku/annoy.rb/blob/main/LICENSE.txt)
 [![Documentation](http://img.shields.io/badge/api-reference-blue.svg)](https://yoshoku.github.io/annoy.rb/doc/)
 
 Annoy.rb is a Ruby binding for the [Annoy (Approximate Nearest Neighbors Oh Yeah)](https://github.com/spotify/annoy).
 
 ## Installation
@@ -54,10 +54,10 @@
 
 The gem is available as open source under the terms of the [Apache-2.0 License](https://www.apache.org/licenses/LICENSE-2.0).
 
 ## Contributing
 
-Bug reports and pull requests are welcome on GitHub at https://github.com/yoshoku/annoy.rb. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [code of conduct](https://github.com/yoshoku/annoy.rb/blob/master/CODE_OF_CONDUCT.md).
+Bug reports and pull requests are welcome on GitHub at https://github.com/yoshoku/annoy.rb. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [code of conduct](https://github.com/yoshoku/annoy.rb/blob/main/CODE_OF_CONDUCT.md).
 
 ## Code of Conduct
 
-Everyone interacting in the Annoy.rb project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/yoshoku/annoy.rb/blob/master/CODE_OF_CONDUCT.md).
+Everyone interacting in the Annoy.rb project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the [code of conduct](https://github.com/yoshoku/annoy.rb/blob/main/CODE_OF_CONDUCT.md).