Add required star when table format

[jneiluj]

Q	A
Is bugfix?	❌
New feature?	✔️
Breaks backward-compatibility?	❌
Tests pass?	✔️
Fixed issues
Updated README/docs?	❌
Added CHANGELOG entry?	❌

Add a red star to cell header in table format for Spectre theme.

[schmunk42]

Could you add a test/use-case/example, I was unable to verify.

[jneiluj]

Could you add a test/use-case/example, I was unable to verify.

{
  "title": "Table with red star",
  "type": "array",
  "format": "table",
  "items": {
    "type": "object",
    "required": [
      "string1",
      "string2"
    ],
    "properties": {
      "string1": {
        "type": "string"
      },
      "string2": {
        "type": "string"
      },
      "string3": {
        "type": "string"
      }
    }
  }
}

Tell me if more is needed.

[schmunk42]

Could you add the required class for (all) the other themes also.
I created a test here: fe99231 (currently checks spectre and bootstrap4)

Branch: https://github.com/json-editor/json-editor/compare/jneiluj-enhance-spectre-theme

I think I can not push onto your PR branch.

[germanbisurgi]

status?

[jneiluj]

I will do, I need time (quite busy atm).

[afmartin3z]

status?