Clarify how to update + add DWL (closes #551, #547)

readme.md

@@ -37,6 +37,7 @@ The following desktop environments were tested with success:
  - budgie
  - cinnamon
  - deepin
+ - dwl
  - dwm
  - enlightenment
  - gnome
@@ -126,7 +127,6 @@ then you have to disable getty, so it doesn't respawn on top of ly
 ```
 
 ### runit
-
 ```
 # zig build installrunit
 # ln -s /etc/sv/ly /var/service/
@@ -148,6 +148,20 @@ you should disable the agetty-tty2 service like this:
 # rm /var/service/agetty-tty2
 ```
 
+### Updating
+You can also install Ly without copying the system service and the configuration file. That's
+called *updating*. To update, simply run:
+
+```
+# zig build installnoconf
+```
+
+If you want to also copy the default config file (but still not the system service), run:
+
+```
+# zig build installexe
+```
+
 ## Arch Linux Installation
 You can install ly from the [`[extra]` repos](https://archlinux.org/packages/extra/x86_64/ly/):
 ```