add --caption to send-file

[lightaffaire]

$ npx mudslide@latest send-file me /tmp/file.txt --caption "here is the file"

make send-file the same as send-image and allow --caption option

[create-issue-branch[bot]]

Branch issue-27-add_--caption_to_send-file created!

[robvanderleek]

Hi @lightaffaire

I've also added the --caption option to the send-file command, thanks for the feedback.