Update README.md (the origin) (#1736)

* made it more  c l e a r e r

* add .

* Update README.md

* Capitalised HTTPS

* update actions to build

* fixed typo

Fixed the bullet point spacing, removed http://mitm.it as the download page don't exist anymore, added `mitmproxy-ca-cert.cer` and save script into the instruction.

* added additional info about mitmproxy