Rename main stream branch: master -> main

Author: kateinoigakukun

.github/workflows/documentation.yml

@@ -2,7 +2,7 @@ name: Documentation
 
 on:
   push:
-    branches: [master]
+    branches: [main]
 
 jobs:
   swift-doc:

README.md

@@ -1,6 +1,6 @@
 # JavaScriptKit
 
-![Run unit tests](https://github.com/swiftwasm/JavaScriptKit/workflows/Run%20unit%20tests/badge.svg?branch=master)
+![Run unit tests](https://github.com/swiftwasm/JavaScriptKit/workflows/Run%20unit%20tests/badge.svg?branch=main)
 
 Swift framework to interact with JavaScript through WebAssembly.
 
@@ -71,4 +71,4 @@ let swiftPet: Pet = try JSValueDecoder().decode(from: jsPet)
 alert("Swift is running on browser!")
 ```
 
-Please see [Example](https://github.com/swiftwasm/JavaScriptKit/tree/master/Example) directory for more information
+Please see [Example](https://github.com/swiftwasm/JavaScriptKit/tree/main/Example) directory for more information