Update README.md

Author: Ankam Ravi Kumar

README.md

@@ -8,7 +8,7 @@ If you do not learn below commands also fine but i personally recommend you to l
 
 [103 Linux Commands Video Tutorial](https://www.youtube.com/watch?v=VG-MMju9RhQ&list=PLHyfPDPl-JDX_dfDEpsvglu4x3h1RjPkz)
 
-alias and unalias, arch, arp-Done, at-Done, awk-Done, bc-Done, blkid, cal-Done, cat-Done, cd-Done, chage-Done, chattr-Done, chgrp-Done, chmod-Done, chown-Done, cp-Done, cpio-Done, crontab-Done, curl-Done, cut-Done, date-Done, dd-Done, df-Done, diff-Done, dig-Done, dnf, du-Done, expr-Done, fdisk, file, find, firewall-cmd, free, ftp, grep, head, history, hostname, id, ifconfig, iostat, ip, kill, last, lessandmore, ln, locate, lpstatandlpadmin, ls, lsof, lspci, mail, man, mdadm, mkdirandrmdir, mkisofs, mount, mutt, mv, nano, netstat, nice, renice, nslookup, passwd, pam_tally2, paste, ping, perloneliner, pkill, ps, pwd, reboot, poweroff, rm, rpm, rsync, scp, screen, sed, sort, ss, ssh, sysctl, tail, tar, tcpdump, top, touch, tr, traceroute, umask, uname, uniq, uptime, useradd, vi, vmstat, w, who, watch, wc, wget, ypcat, yppasswd, yum, zip, sar
+alias and unalias, arch, arp, at, awk, bc, blkid, cal, cat, cd, chage, chattr, chgrp, chmod, chown, cp, cpio, crontab, curl, cut, date, dd, df, diff, dig, dnf, du, expr, fdisk, file, find, firewall-cmd, free, ftp, grep, head, history, hostname, id, ifconfig, iostat, ip, kill, last, lessandmore, ln, locate, lpstatandlpadmin, ls, lsof, lspci, mail, man, mdadm, mkdirandrmdir, mkisofs, mount, mutt, mv, nano, netstat, nice, renice, nslookup, passwd, pam_tally2, paste, ping, perloneliner, pkill, ps, pwd, reboot, poweroff, rm, rpm, rsync, scp, screen, sed, sort, ss, ssh, sysctl, tail, tar, tcpdump, top, touch, tr, traceroute, umask, uname, uniq, uptime, useradd, vi, vmstat, w, who, watch, wc, wget, ypcat, yppasswd, yum, zip, sar
 
 After that start learning shell scripting using below topics