Fix typo.

Author: ltratt

README.md

@@ -12,8 +12,8 @@ user-specified command (e.g. `cargo check`) as an oracle to tell if its
 reduction of an item's visibility is valid or not. Note that `depub` is
 entirely guided by the oracle command: if the code it compiles happens not to
 use part of an intentionally public interface, then `depub` is likely to
-suggest reducing its visibility even though that's what you want. The broader
-the coverage of your oracle, the less this is an issue.
+suggest reducing its visibility even though that's not what you want. The
+broader the coverage of your oracle, the less this is an issue.
 
 In essence, `depub` does a string search for `pub`, replaces it with `pub
 crate` and sees if a test command still succeeds. If it does, it keeps that