Add certificate configuration for CasaOs

Add please configuration instruction for certificate after installing Crafty to Casaos.

## Generate certificate

1. Connect via ssh to your server
2. Go to certs directory `ssh
   cd /DATA/AppData/crafty/config/web/certs`

3. Run command `ssh
openssl req -x509 -nodes -days 365 -newkey rsa:2048 \
  -keyout privkey.pem \
  -out fullchain.pem \
  -subj "/C=US/ST=State/L=City/O=Organization/CN=your-local-ip"`