Improve error description of ft-mint?

Author: friedger

clarity/src/vm/docs/mod.rs

@@ -2082,7 +2082,8 @@ type defined using `define-fungible-token`. The increased token balance is _not_
 rather minted.  
 
 If a non-positive amount is provided to mint, this function returns `(err 1)`. Otherwise, on successfuly mint, it
-returns `(ok true)`.
+returns `(ok true)`. If this call would result in more supplied tokens than defined by the total supply in 
+`define-fungible-token`, then a `SupplyOverflow` runtime error is thrown.
 ",
     example: "
 (define-fungible-token stackaroo)