unidiomatic-typecheck has descriptive rather than prescriptive lint message text

[gpshead]

https://github.com/PyCQA/pylint/blob/master/pylint/checkers/base.py#L2314 unidiomatic-typecheck

The error message is currently along the lines of:

Using type() instead of isinstance() for a typecheck. [unidiomatic-typecheck]

which is easy for users to misread as "use type instead of isinstance" which is the opposite of what we want and is what their code already does, leaving them wondering what they're not seeing. The sentence isn't obviously stating that what it describes is a problem and doesn't directly suggest the solution.

I suggest rewording this lint message short description to be prescriptive

Use isinstance() rather than type() comparisons for a typecheck.

(this wording exists up through at least pylint 2.6.0)

[hippo91]

@gpshead thanks! I totally agree with you.
Would you mind making a PR for this?