Add note on v5 version jump

Author: hectormmg

README.md

@@ -45,6 +45,7 @@ The [`lib`](https://github.com/AzureAD/microsoft-authentication-library-for-js/t
 - The MSAL team provides full support to the current version for each package in the table below.
 - LTS (long-term support) versions will still receive support and bug-fixes but will not ship new features.
 - Versions in Critical Security Support will only receive fixes for critical security bugs.
+- All supported packages were brought up to version parity as of `v5`. Packages with versions lower than `v4` in the LTS column skipped as many versions as required to jump directly to `v5`.
 
 
 ### Package Structure