Support for highlighting in plain text annotation

[Travcort]

Problem:

From using v3 in my application, I have noticed that the annotatePlainText method on notionToMarkdown class here, does not convert highlighted text into any kind of highlighting for the markdown.

For example:
For the "loves or pursues or desires to obtain pain of itself, because it is pain" phrase as written in Notion:

The Official Notion API returns:

{
  "type": "text",
  "text": {
    "content": "loves or pursues or desires to obtain pain of itself, because it is pain",
    "link": null
  },
  "annotations": {
    "bold": false,
    "italic": false,
    "strikethrough": false,
    "underline": false,
    "code": false,
    "color": "default"
  },
  "plain_text": "loves or pursues or desires to obtain pain of itself, because it is pain",
  "href": null
}

NB: The "color" property for annotations is "default" in the case where a colored background is used

For the "circumstances occur in which toil and pain can procure him some great" phrase as written in Notion,

The Official Notion API returns:

{
  "type": "text",
  "text": {
    "content": "circumstances occur in which toil and pain can procure him some great",
    "link": null
  },
  "annotations": {
    "bold": false,
    "italic": false,
    "strikethrough": false,
    "underline": false,
    "code": false,
    "color": "yellow"
  },
  "plain_text": "circumstances occur in which toil and pain can procure him some great",
  "href": null
}

NB: The "color" property for annotations is the color used in the case where colored text is used

Solution:

My proposal would be to convert the color annotation to highlighting using the ==${text}== style since that property exists in the official Notion API but is unused in your implementation.