master -> main, update docs

Author: alexcmgit

README.md

@@ -13,9 +13,9 @@
 This package is not published to npm yet, you need to install using [gitpkg](https://gitpkg.now.sh/).
 
 ```shell
-npm install https://gitpkg.now.sh/alexrintt/gatsby-source-github-graphql/packages/gatsby-source-github-graphql?master
+npm install https://gitpkg.now.sh/alexrintt/gatsby-source-github-graphql/packages/gatsby-source-github-graphql?main
 # or
-yarn add https://gitpkg.now.sh/alexrintt/gatsby-source-github-graphql/packages/gatsby-source-github-graphql?master
+yarn add https://gitpkg.now.sh/alexrintt/gatsby-source-github-graphql/packages/gatsby-source-github-graphql?main
 ```
 
 ## Usage

packages/gatsby-source-github-graphql-discussions/README.md

@@ -3,9 +3,9 @@
 To install this package just run:
 
 ```shell
-npm install https://gitpkg.now.sh/alexrintt/gatsby-source-github-graphql/packages/gatsby-source-github-graphql-discussions?master
+npm install https://gitpkg.now.sh/alexrintt/gatsby-source-github-graphql/packages/gatsby-source-github-graphql-discussions?main
 # or
-yarn add https://gitpkg.now.sh/alexrintt/gatsby-source-github-graphql/packages/gatsby-source-github-graphql-discussions?master
+yarn add https://gitpkg.now.sh/alexrintt/gatsby-source-github-graphql/packages/gatsby-source-github-graphql-discussions?main
 ```
 
 ## Usage