Checklist for 6.0.0

[smoelius]

• Eliminate this MSRV policy:

  dylint/README.md

  Lines 226 to 230 in dacf1aa

  	## MSRV policy
  	A bump of the Dylint library's MSRV will be accompanied by a bump of at least Dylint's minor version.
  	Put another way, we strive to preserve Dylint's MSRV when releasing bug fixes, and to change it only when releasing new features.

  
  The intent is good. But if there is a change in master that bumps the MSRV, either bug fixes cannot be published, or bug fixes must be published with a minor version bump.