Minor README.md grammar correction.

README.md

@@ -53,6 +53,5 @@ Improvements over EEP0018
 
 Jiffy should be in all ways an improvemnt over EEP0018. It no longer
 imposes limits on the nesting depth. It is capable of encoding and
-decoding large numbers and it does quite a bit more checking for validity
-of valid UTF-8 in strings.
+decoding large numbers and it does quite a bit more validation of UTF-8 in strings.