Proposed change

Config flow has markdown in descriptions.
Why not do the same for service/action parameter descriptions too?

Example strings.json in core (markdown was appended to the description field for showcase):

{
  "services": {
    "create": {
      "description": "Creates a new scene.",
      "fields": {
        "scene_id": {
          "description": "The entity ID of the new scene.\n\nExample: *italics* _underline_ **bold** `code`\n[links](http://example.com) open in new window.",
          "name": "Scene entity ID"
        }
    }
  }
}

How it looks like:

Type of change

• Dependency upgrade
• Bugfix (non-breaking change which fixes an issue)
• New feature (thank you!)
• Breaking change (fix/feature causing existing functionality to break)
• Code quality improvements to existing code or addition of tests

Example configuration

None required.

Additional information

• This PR fixes or closes issue: fixes #
• This PR is related to issue or discussion:
• Link to documentation pull request:

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• Tests have been added to verify that the new code works.

If user exposed functionality or configuration variables are added/changed:

• Documentation added/updated for www.home-assistant.io