Rename double negations.

[mysticatea]

I have made a ton of rules which have double negation in their name, e.g. vue/no-invalid-v-for.
However, double negations are a bad choice.

Do we have the chance that we rename those rules before the official release?
For example:

• vue/no-invalid-v-for → vue/validate-v-for or something like.

Though, I'm not sure that it's valuable even if compatibility confusion happens... 🤔

[michalsnik]

Given that it's still in beta (with all those rules) and when we release it officially it will be v4.0.0 I think we can change the naming. In fact it's the last moment we can do it without bigger consequences, but we should add a table in Readme with mappings to 3.x names