Improve docstring for the invert function.
(defn invert
`Returns a table where the keys of an associative data structure
- are the values, and the values of the keys. If multiple keys have the same
- value, one key will be ignored.`
+ are the values, and the values are the keys. If multiple keys in the
+ original mapped to the same value, only one of those values will
+ become a key in the returned table.`
[ds]
(def ret @{})
(loop [k :keys ds]
