how to add command tree in centos7 code example

Example 1: terminal tree command

# yum install tree	 #RHEL/CentOS 7
# dnf install tree	 #Fedora 22+ and /RHEL/CentOS 8
$ sudo apt install tree	 #Ubuntu/Debian
# sudo zypper in tree 	 #openSUSE

Example 2: bash: tree: command not found... centos7

# yum install tree -y