Docs: isGlobal option does not default to true (#142)

The value has been auto-detected since #114

Author: dideler

readme.md

@@ -142,7 +142,7 @@ Message that will be shown when an update is available.
 ##### isGlobal
 
 Type: `boolean`<br>
-Default: `true`
+Default: auto-detect
 
 Include the `-g` argument in the default message's `npm i` recommendation. You may want to change this if your CLI package can be installed as a dependency of another project, and don't want to recommend a global installation. This option is ignored if you supply your own `message` (see above).