docs: fix a broken link to MS Terminology Search (#1341)

docs/api.md

@@ -946,7 +946,7 @@ To submit a new translation for yargs:
 1. use `./locales/en.json` as a starting point.
 2. submit a pull request with the new locale file.
 
-*The [Microsoft Terminology Search](http://www.microsoft.com/Language/en-US/Search.aspx) can be useful for finding the correct terminology in your locale.*
+*The [Microsoft Terminology Search](https://www.microsoft.com/en-us/language/Search) can be useful for finding the correct terminology in your locale.*
 
 <a name="middleware"></a>.middleware(callbacks, [applyBeforeValidation])
 ------------------------------------