Expose on paste event api

[einer20]

We are facing a situation where our editors are coping/pasting table from GDocs or Word but when they paste the table we are getting the following content on the markdown textarea:

Property Name
Data type
Default value
required
sponsorName
varchar

When we should be getting(the following markdown was pasted from a google doc table to here which means its possible):

  | Property Name | Data type | Default value
-- | -- | -- | --
required | sponsorName | varchar |  

If we have on pasted event, we could be able to transform the event data to valid a markdown or whatever the format is to a valid markdown.