Installation and usage on linux

[SlokAks]

I downloaded the binary file cses-cli_latest_linux_amd64 for Ubuntu 20.04. And, then installed lynx as mentioned in README.md. I changed the name of the binary file to cses-cli in PATH(Desktop).

To successfully run it, I had to use :
chmod +x cses-cli

and then run as :
./cses-cli
./cses-cli login
./cses-cli list
etc

I think this should be mentioned in the README.md file.