Add PlaceholderAPI dependency disclaimer

README.md

@@ -1,8 +1,11 @@
 # NounsPicker
 
-This plugin allows users to pick their own preferred pronouns, that are then passed as PlaceholderAPI arguments to use
+This plugin allows users to pick their own preferred pronouns, that are then passed as **PlaceholderAPI** arguments to use
 wherever you want to. The pronouns are picked from a predefined list that only administrators can modify.  
   
+***The plugin depends on [PlaceholderAPI](https://github.com/PlaceholderAPI/PlaceholderAPI).***  
+  
+    
 ## Basic info
 ### Commands
 - `/nouns create <pronoun> <format>`: add a new pronoun to the database.