update keys_only snippet discription, changed func param to flat_dict

snippets/keys_only.md

@@ -2,12 +2,12 @@
 
 Function which accepts a dictionary of key value pairs and returns a new flat list of only the keys.
 
-Uses the .items() function with a for loop on the dictionary to track both the key and value and returns a new list by appending the keys to it. Best used on 1 level-deep key:value pair dictionaries and not nested data-structures.
+Uses the .items() function with a for loop on the dictionary to track both the key and value and returns a new list by appending the keys to it. Best used on 1 level-deep key:value pair dictionaries (a flat dictionary) and not nested data-structures which are also commonly used with dictionaries. (a flat dictionary resembles a json and a flat list an array for javascript people).
 
 ``` python
-def keys_only(dict):
+def keys_only(flat_dict):
     lst = []
-    for k, v in dict.items():
+    for k, v in flat_dict.items():
         lst.append(k)
     return lst
 ```