* modified gitignore
* fixing gitignore
* reomving the himalaya.iml file
* applied cargo fmt
* fixed typo in .gitignore and removed an entry in it
* adding gitignore to cli/
* reducing .gitignore in cli to one line
* Default Content-Type to text/plain for not multipart messages
Parse body of messages without subparts as text/plain if Content-Type
header is not set.
* narrow check for defaulting to `text/plain`
take message body as `text/plain` only if message has only one part
and has no `Content-Type` header
Co-authored-by: Clément DOUIN <soywod@users.noreply.github.com>