Wcag - warnings

[emilos]

We could implement few simple wcag rules:

img should always have an alt attribute

We should show the warnings durign compilation. You should be able to turn off the warnings.

Ideally we should reuse other lib.

[emilos]

We could try to implement the rules in a reusable json format, e.g.

{
  "rules": [
    {
      "name": "alt-required",
      "tags": ["image"],
      "attributes": ["alt"],
      "rule": ["required"]
    }
  ]
}