docs: sourceMaps are disabled by default (#890)

mweibel · evilebottnawi · commit 2a2ee7b3a75a · 2019-01-28T13:07:58.000+03:00
diff --git a/README.md b/README.md
@@ -490,7 +490,7 @@ module.exports = {
 ### `sourceMap`
 
 Type: `Boolean`
-Default: `true`
+Default: `false`
 
 To include source maps set the `sourceMap` option.
 
