Add formatting check for missing header

[MollyMaclachlan]

Currently, there is no formatting check to detect if the correct type of header is missing from the transcription. Using this post as an example, and ignoring the other formatting issues in it,

we can see that the user has used the title of the post as their header. It should be relatively easy to add a check to see if the transcription contains one of the following: *Audio Transcription*, *Image Transcription*, or *Video Transcription*.

If none of these are included in the transcription, it should be rejected with an explanation of proper header formatting. Whether or not a colon is included and any content after the colon should not be checked, as these can be optional depending on the post.

I would also suggest detecting what type of post (audio/image/video) it is via the title of the submission and specifically only recommending the appropriate header, but not being familiar with the code I don't know how easy to do this would be.