Add PKGBUILD and update Arch installation guide

README.md

@@ -23,10 +23,39 @@ I haven't kept `man dwm`/`dwm.1` updated though. PRs welcome on that, lol.
 - [vanitygaps](https://dwm.suckless.org/patches/vanitygaps/): Gaps allowed across all layouts.
 - [swallow patch](https://dwm.suckless.org/patches/swallow/): if a program run from a terminal would make it inoperable, it temporarily takes its place to save space.
 
+## Installation on Arch Linux based distributions
+
+### Download the source code
+
+```bash
+git clone https://github.com/LukeSmithxyz/dwm.git
+cd dwm
+```
+
+### Configure
+
+To use a custom `config.h`, place it in the package directory.
+
+### Compile and install
+
+To compile dwm you need to install the `base-devel` package group if you haven't done it previously.
+
+If you have `paru` installed:
+
+```bash
+paru -Ui
+```
+
+Otherwise:
+
+```bash
+makepkg -cirs
+```
+
 ## Installation for newbs
 
-```
-git clone https://github.com/LukeSmithxyz/dwm
+```bash
+git clone https://github.com/LukeSmithxyz/dwm.git
 cd dwm
 sudo make install
 ```