Allow the removing of some unwanted characters in selector results

[algolia]

Allow the removing of some unwanted characters in selector results

[redox]

@pixelastic should we leverage the new "selectors" object to avoid stripping those expressions from the text?

"selectors": {
  "lvl0": {
    "selector": "h1",
    "strip_chars": ["¶"]
  }
}

Or maybe we could have both the "strip_chars" option at the selector level and at the root level?

[pixelastic]

@redox : I like this idea. Having it both on the root (as a default value for all selectors) as well as on each selector (overriding the default value).

[redox]

👍

[maxiloc]

We won't have the array syntax for this param. It should be in another option

[maxiloc]

Fixed with #43