add `showOnColon` to language specific settings

[unional]

showOnColon is great for text, such as markdown, git commit, and plaintext.

But for programming languages, it could be too intrusive. (e.g. JavaScript/TypeScript ternary operator, CSS, etc).

So it would be great if we can do this:

{
  "emojisense.showOnColon": false // disable by default
  "emojisense.languages": {
    "markdown": {
      "showOnColon": true // enable specifically
    }
  }
}

or

{
  "emojisense.showOnColon": true // enable by default
  "emojisense.languages": {
    "typescript": {
      "showOnColon": false, // disable specifically
      "markupCompletionsEnabled": false,
      "emojiDecoratorsEnabled": false      
    }
  }
}

btw, setting markupCompletionsEnabled and emojiDecoratorsEnabled to be false by default for programming languages would be great because the markup will not be valid syntax in programming languages.