Escape plain text description hover correctly

[Legend-Master]

This matches the behavior with the documentation shown in the autocomplete

With this schema:

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "properties": {
    "test": {
      "description": "For example:\n\n<script>\n  alert(1)\n</script>\n\n    Test [1]"
    }
  }
}

Before:

After: