pacman: add sudo and use long options (#7132)

pages/linux/pacman.md

@@ -6,15 +6,15 @@
 
 - Synchronize and update all packages:
 
-`pacman --sync --refresh --sysupgrade`
+`sudo pacman --sync --refresh --sysupgrade`
 
 - Install a new package:
 
-`pacman --sync {{package_name}}`
+`sudo pacman --sync {{package_name}}`
 
 - Remove a package and its dependencies:
 
-`pacman --remove --recursive {{package_name}}`
+`sudo pacman --remove --recursive {{package_name}}`
 
 - Search the package database for a regular expression or keyword:
 
@@ -34,4 +34,4 @@
 
 - Empty the entire pacman cache:
 
-`pacman --sync --clean --clean`
+`sudo pacman --sync --clean --clean`