Adithya/bug fixes (#12)

* file size for a single upload limited to 20 mb

* save work for upload to saved messages

Adithya/implement encrypted file management, security enhanced (#11)

* implement file encryption and decryption

* add backward compatibility for download_file decryption

* alert in homepage if user count is > 2 in channel

* FILE SHARING FEATURE

* update doc

* implement search functionality + bug fixes

* update doc

Adithya/bulk upload download cli tool (#5)

* cli tool for backup - bulk upload

* update cli bulk upload tool

* bulk download command in cli tool

* path issue during download fixed

* update doc

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Co-authored-by: adithyaamara <adithya.amara@gmail.com>