reformat ISO building part of README

Author: beans9926

README.md

@@ -105,24 +105,25 @@ Packages in TCET Linux is managed by package manager.
 
 # How to build ISO
 
-## Install required package
+### 1. Build ( Using Script )
 ```bash
-sudo pacman -S archiso
+cd tcet-linux
+./buildiso
 ```
+OR
+### 2. Build ( Manually )
 
-## Clone repository
+**Install required package**
 ```bash
-git clone https://github.com/tcet-opensource/tcet-linux.git
+sudo pacman -S archiso
 ```
 
-## Build ( Using Script )
+**Clone repository**
 ```bash
-cd tcet-linux
-./buildiso
+git clone https://github.com/tcet-opensource/tcet-linux.git
 ```
-OR
-## Build ( Manually )
-### Setup Keys
+
+**Setup Keys**
 ```bash
 # Akash6222
 sudo pacman-key --keyserver keyserver.ubuntu.com -r 280178FA27665D44
@@ -141,13 +142,13 @@ sudo pacman-key --keyserver keyserver.ubuntu.com -r BF4E1E687DD0A534
 sudo pacman-key --lsign-key BF4E1E687DD0A534
 
 ```
-### Build ISO
+**Build ISO**
 ```bash
 cd tcet-linux
 sudo mkarchiso -v .
 ```
 
-## ISO will appear in `work/out/` directory
+### ISO will appear in `work/out/` directory
 <br />
 
 ## Important Links: