Add comments to: AttachmentViewMain.swift
It would be nice for everyone participating in this year's software project or those to come to have comments explaining the files a little bit.
I will make the start with 'AttachmentViewMain.swift'
I hope that you will create similar issues where you just add comments to files you worked your head around.
Here you find a Swift Style Guide by Google:
I am looking forward to read more comments by you ;-)