Fix ESLint plugin version.

[cpojer]

6.0.0 of the ESLint plugin was released accidentally as per (facebook/react#32982 (comment)). However, when using a ^ for the version range, 6.0.0 takes precedence over 6.0.0-rc.1.

This PR fixes the blog post to lock the version to 6.0.0-rc.1.

If possible, please release 6.1.0-rc.1 of the plugin instead to ensure 6.0.0 will not accidentally be installed.

[cpojer]

Also added a sentence explaining that the rule needs to be explicitly enabled since it is not enabled by default (see https://github.com/facebook/react/blob/main/packages/eslint-plugin-react-hooks/src/index.ts#L21-L24) and the rule's existence is not mentioned in the README of the package.

It would be great to add a strict config to the ESLint plugin that will enable and error on all rules.

[cpojer]

cc @poteto @josephsavona

[poteto]

Thanks! Good call about rereleasing, I hadn't realized the caret range would pick up a deprecated package