[ Using a flag ] allow adding custom lines of text to the screenfetch output

[takattila]

Example command

export WAN_IP="IP 'WAN'=$(curl -s ipinfo.io/ip)"
export PRIVATE_IP="IP 'PRIVATE'=$(hostname -I | awk '{print $1}')"
export WEB_TERMINAL="Web terminal interface=http://$(hostname -I | awk '{print $1}'):8181"

screenfetch -C ",${WAN_IP},${PRIVATE_IP},,${WEB_TERMINAL}"

Example output

                                       takattila@takattilapc
 MMMMMMMMMMMMMMMMMMMMMMMMMmds+.        OS: Linuxmint 20.1 ulyssa
 MMm----::-://////////////oymNMd+`     Kernel: x86_64 Linux 5.4.0-65-generic
 MMd      /++                -sNMd:    Uptime: 1h 8m
 MMNso/`  dMM    `.::-. .-::.` .hMN:   Packages: 2498
 ddddMMh  dMM   :hNMNMNhNMNMNh: `NMm   Shell: zsh 5.8
     NMm  dMM  .NMN/-+MMM+-/NMN` dMM   Disk: 320G / 922G (36%)
     NMm  dMM  -MMm  `MMM   dMM. dMM   CPU: AMD Phenom II X4 940 @ 4x 3GHz
     NMm  dMM  -MMm  `MMM   dMM. dMM   GPU: NVIDIA Corporation GK208B [GeForce GT 710] (rev a1)
     NMm  dMM  .mmd  `mmm   yMM. dMM   RAM: 1230MiB / 7961MiB
     NMm  dMM`  ..`   ...   ydm. dMM
     hMM- +MMd/-------...-:sdds  dMM   IP 'WAN': 96.123.256.22
     -NMm- :hNMNNNmdddddddddy/`  dMM   IP 'PRIVATE': 10.1.1.10
      -dMNs-``-::::-------.``    dMM
       `/dMNmy+/:-------------:/yMMM   Web terminal interface: http://10.1.1.10:8181
          ./ydNMMMMMMMMMMMMMMMMMMMMM
             \.MMMMMMMMMMMMMMMMMMM

[KittyKatt]

Looks good to me. Merging.