update MSRV policy section

Author: newpavlov

README.md

@@ -14,9 +14,9 @@ Collection of password hashing algorithms, otherwise known as password-based key
 
 Please see the [OWASP Password Storage Cheat Sheet] for assistance in selecting an appropriate algorithm for your use case.
 
-### MSRV policy
+### Minimum Supported Rust Version (MSRV) Policy
 
-In future Minimum Supported Rust Version (MSRV) can be changed, but it will be done with a minor version bump.
+MSRV bumps are considered breaking changes and will be performed only with minor version bump.
 
 ## License