Markdown processing

[turt2live]

This is what Slack wants

{
    "text": "*bold* `code` _italic_ ~strike~",
    "username": "markdownbot",
    "mrkdwn": true
}

This will use the mrkdwn property if it exists, but otherwise assume format as the default, ie:

{
    "text": "*bold* `code` _italic_ ~strike~",
    "username": "markdownbot",
    "format": "markdown"
}

[turt2live]

Further support the mrkdwn_in field. This is an array of fields with markdown in them.

[whoracle]

What is the status of this? I've been trying for a while to get code to look right via the webhook, and from this issue it's not really clear (to me at least) if and how the formatting via webhooks works...