README.md in opentelemetry-instrumentation-rails-0.12.0 vs README.md in opentelemetry-instrumentation-rails-0.13.0

@@ -30,11 +30,11 @@
 end
 ```
 
 ## Examples
 
-Example usage can be seen in the `./example/trace_demonstration.rb` file [here](https://github.com/open-telemetry/opentelemetry-ruby/blob/master/instrumentation/rails/example/trace_request_demonstration.ru)
+Example usage can be seen in the `./example/trace_demonstration.rb` file [here](https://github.com/open-telemetry/opentelemetry-ruby/blob/main/instrumentation/rails/example/trace_request_demonstration.ru)
 
 ## How can I get involved?
 
 The `opentelemetry-instrumentation-rails` gem source is [on github][repo-github], along with related gems including `opentelemetry-api` and `opentelemetry-sdk`.
 
@@ -45,9 +45,9 @@
 The `opentelemetry-instrumentation-rails` gem is distributed under the Apache 2.0 license. See [LICENSE][license-github] for more information.
 
 [rails-home]: https://github.com/rails/rails
 [bundler-home]: https://bundler.io
 [repo-github]: https://github.com/open-telemetry/opentelemetry-ruby
-[license-github]: https://github.com/open-telemetry/opentelemetry-ruby/blob/master/LICENSE
+[license-github]: https://github.com/open-telemetry/opentelemetry-ruby/blob/main/LICENSE
 [ruby-sig]: https://github.com/open-telemetry/community#ruby-sig
 [community-meetings]: https://github.com/open-telemetry/community#community-meetings
 [ruby-gitter]: https://gitter.im/open-telemetry/opentelemetry-ruby