Update README.md

Author: torum

README.md

@@ -63,9 +63,12 @@ Image Viewer can be launched via command-line, and applications or scripts can a
 ` $ ImageViewer -i 2 -f on -o on -e off C:\Users\<USER>\Pictures\Wallpapers\` 
 
 #### Build instruction:   
+
 You can download the Lazarus IDE and FPC(compiler) from here.
 https://www.lazarus-ide.org/index.php?page=downloads
 
+Or `sudo apt install lazarus-ide`
+
 Once you download and install the IDE, just open the project file "ImageViewer.lpr".
 When the project is opened, just hit F9 and run.