Relocate Archlinux code snippet to avoid confusion

Close #185

lkmpg.tex

@@ -204,17 +204,17 @@ sudo apt-get update
 apt-cache search linux-headers-`uname -r`
 \end{codebash}
 
-On Arch Linux:
-\begin{codebash}
-sudo pacman -S linux-headers
-\end{codebash}
-
 This will tell you what kernel header files are available.
 Then for example:
 \begin{codebash}
 sudo apt-get install kmod linux-headers-5.4.0-80-generic
 \end{codebash}
 
+On Arch Linux:
+\begin{codebash}
+sudo pacman -S linux-headers
+\end{codebash}
+
 \section{Examples}
 \label{sec:examples}
 All the examples from this document are available within the \verb|examples| subdirectory.