docs(examples): prevent internal imports via eslint

[Fabianopb]

Following up #3494 , @levithomason had the idea to prevent local imports in the docs examples via linter. Here's one solution: we have a local .eslintrc in the examples preventing undesired import patterns. However the rule is not valid for the index.js files in the same folder, so I've disabled the rule for those files.

Now the eslint will complain if there's a local import in the examples, like this:

Related to this PR, it seems that the prettier has done some additional changes to some of the index.js files. The docs seem to still work fine, but I wonder why that happened...

I'd be glad to get some feedback!
Cheers!

[codecov-io]

Codecov Report

Merging #3503 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #3503   +/-   ##
=======================================
  Coverage   99.82%   99.82%           
=======================================
  Files         172      172           
  Lines        2804     2804           
=======================================
  Hits         2799     2799           
  Misses          5        5

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[layershifter]

Instead of editing all files, I suggest to add overrides:

"overrides": [
 {
  "files": ["index.js"],
     "rules": {
        "no-restricted-imports": "off"   
     }
 }

[Fabianopb]

Well pointed @layershifter, I didn't know you could override rules like this, thanks!

[layershifter]

👍