Add onImgClicked for MarkDown

[equationl]

Add a parameter ‘onImgClicked’ for RichTextScope.Markdown which invoke when a picture is clicked.

Here some samples:

Android:

Markdown(
  content = sampleMarkdown,
  onImgClicked = {
    Toast.makeText(context, it, Toast.LENGTH_SHORT).show()
  }
)

device-2023-07-21-100558.webm

Desktop:

Markdown(
  content = text,
  onImgClicked = {
    println("Click img: $it")
  }
)

20230721100840.mp4