Added CLI option to upload media in tweet

[Rishikant181]

To upload media while posting a tweet, use the -m or --media option along with path(s) to media items(s) as follows:

rettiwt tweet post "I love coding!" -m "<path_to_media1>;<path_to_media2>;<path_to_media3>"

Where

• is the path to the media item to upload.
• ';' is the delimiter.