Preserve supported markdown formatting when pasting into composer

Often we have content that is formatted in Markdown that we’d like to paste into Intercom to be sent as a reply to a customer. It’d be great if pasted markdown formatting was preserved where that formatting is supported by Intercom. A quick test gave me these results:

Not preserved on paste:

• Bold: **text**
• Italic: _text_ and *text*
• Strikethrough: ~~text~~
• Inline code: `text`
• Code block: triple backticks
• Heading: # (H1) and ## (H2)
• Blockquote: > text
• Bulleted list: - item and * item
• Numbered list: 1. (pastes as plain text, not a styled list)

Already handled correctly on paste, for contrast:

• Markdown link [label](url) renders as a clickable link
• Single line breaks and blank lines between paragraphs are preserved