Per keyword skill level

[GingrPowr]

Is your feature request related to a problem? Please describe.
In resume it's useful to be able to define the level per skill, and not per category has it's possible right now.
For example:

"skills": [{
  "name": "Web Development",
  "level": "Master",
  "keywords": [
    "HTML",
    "CSS",
    "JavaScript"
  ]

There, only the skill category "Web development" can have a level assigned.

Describe the solution you'd like

"skills": [{
  "name": "Web Development",
  "level": "Master",
  "keywords": [
    { "skill": "HTML", "level": "4/5" },
    { "skill": "CSS", "level": "3/5" },
    { "skill": "JavaScript", "level": "1/5" }
  ]

To be able to assign a level per skill, not to the whole category only.

Describe alternatives you've considered
Using the skill category as a skill, but it's really hard to find a proper theme then: skills would be stylised as headers instead of list items under most themes.

Additional context
If this is already a thing, then the explanation at https://jsonresume.org/schema is not complete.
Also, how the "level" works? Is it possible to use the string as an integer value to display some progression bar/stars? Instead of writting x/5.
Overall I find it hard to have documentation on how skill level works.