Issue 3692 - Add base ESLint configuration

eslint-config-eyeo/README.md

 # eslint-config-eyeo
 
 An [ESLint](http://eslint.org) configuration that checks for compliance with the
-[Adblock Plus coding style guide](https://adblockplus.org/coding-style#javascript).

[Sebastian Noack, 2017/02/10 18:04:31]

This seems a little inconsistent with the decision to name it eslint-config-eyeo
(rather than eslint-config-abp). If we stick to that name, but don't move the
styleguide to eyeo.com yet (we won't), perhaps we should at least clarify that
it's the coding style used by all Eyeo projects, to avoid confusion.

[kzar, 2017/02/10 19:10:44]

Done.

+[Adblock Plus coding style guide](https://adblockplus.org/coding-style#javascript)
+which is used for all eyeo projects.
 
 ## Installation
 
     npm install -g eslint eslint-config-eyeo
 
-(As root, or using sudo.)
+This command requires administrator privileges so you might need to use `sudo`.
 
 ## Usage
 
-To lint a JavaScript file using ESLint you simply run the `eslint` command with
-the file as an argument. For example:
+To lint a JavaScript file using ESLint you run the `eslint` command with the
+file as an argument. For example:
 
     eslint some-file.js
 
-(For advanced usage see `eslint --help`.)
+For advanced usage see `eslint --help`.
 
-Note: If you need to lint files inside projects which do not already have an

[Sebastian Noack, 2017/02/10 18:04:31]

This is not only relevant when linting projects that don't have an ESLint
configuration, but that is also the minimal boilerplate when creating an ESLint
configuration for a project. Mind clarifying that?

[kzar, 2017/02/10 19:10:44]

Done.

-ESLint configuration which extends `eslint-config-eyeo` you can create a
-personal configuration in `~/.eslintrc.json` like so:
+In order to use eslint-config-eyeo your project's ESLint configuration
+should extend from it. A minimal example looks like this:
 
     {
-      "extends": "eslint-config-eyeo"
+      "extends": "eslint-config-eyeo",
+      "root": true
     }
+
+For projects without an ESLint configuration you can create your own
+personal configuration in `~/.eslintrc.json`, but take care to remove
+the `"root": true` section from the above example.