docs: update semantic-release default branch in links

Author: pvdlg

README.md

@@ -23,7 +23,7 @@ $ npm install @semantic-release/npm -D
 
 ## Usage
 
-The plugin can be configured in the [**semantic-release** configuration file](https://github.com/semantic-release/semantic-release/blob/caribou/docs/usage/configuration.md#configuration):
+The plugin can be configured in the [**semantic-release** configuration file](https://github.com/semantic-release/semantic-release/blob/master/docs/usage/configuration.md#configuration):
 
 ```json
 {
@@ -66,7 +66,7 @@ Use either `NPM_TOKEN` for token authentication or `NPM_USERNAME`, `NPM_PASSWORD
 
 **Note**: The `pkgRoot` directory must contains a `package.json`. The version will be updated only in the `package.json` and `npm-shrinkwrap.json` within the `pkgRoot` directory.
 
-**Note**: If you use a [shareable configuration](https://github.com/semantic-release/semantic-release/blob/caribou/docs/usage/shareable-configurations.md#shareable-configurations) that defines one of these options you can set it to `false` in your [**semantic-release** configuration](https://github.com/semantic-release/semantic-release/blob/caribou/docs/usage/configuration.md#configuration) in order to use the default value.
+**Note**: If you use a [shareable configuration](https://github.com/semantic-release/semantic-release/blob/master/docs/usage/shareable-configurations.md#shareable-configurations) that defines one of these options you can set it to `false` in your [**semantic-release** configuration](https://github.com/semantic-release/semantic-release/blob/master/docs/usage/configuration.md#configuration) in order to use the default value.
 
 ### Npm configuration