fix(store): update installation of the NgRx ESLint Plugin

[timdeschryver]

PR Checklist

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https:/ngrx/platform/blob/master/CONTRIBUTING.md#commit
• Tests for the changes have been added (for bug fixes / features)
• Documentation has been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

[x] Bugfix
[ ] Feature
[ ] Code style update (formatting, local variables)
[ ] Refactoring (no functional changes, no api changes)
[ ] Build related changes
[ ] CI related changes
[x] Documentation content changes
[ ] Other... Please describe:

What is the current behavior?

Closes #

What is the new behavior?

Does this PR introduce a breaking change?

[ ] Yes
[x] No

Other information

This PR updates the installation and the docs of the NgRx ESLint plugin.
An overview of the changes:

• install v2 of the plugin, this is required for projects that use the latest version of the typescript plugin (installed with the Angular ESLint plugin)
• the plugin has better configuration files, meaning that we can simply extend it now instead of configuring it manually
• updated the config to make it consistent with the Angular ESLint plugin (we add a new override to the plugin instead of modifying an existing one)