[Documentation] Add Features List to README.md

[falcon78921]

Some features to note:
--> Add/Remove APs
--> Add/Remove AP Groups
--> Add/Remove SSIDs
--> Basic Network Toolkit (i.e. ping, traceroute, curl, dig)
--> Support for 802.1x SSID Deployments
--> SSH Password Encryption/Decryption (via Fernet)