Update README.md

- Add example of output
- Edit description of the behavior of the art selection algorithm

README.md

@@ -1,11 +1,21 @@
 # mycfetch
 
-Simple neofetch.  
+Simple fetch
+
+```
+$ mycfetch cat
+ ╱|、     naki@nakidai
+(˚ˎ。7    --
+| 、˜〵   Linux 6.10.0-rc3-ga3e18a540541
+じしˍ,)ノ Up 2 hours, 20 minutes
+```
 
 Usage
 --
-Use argument to select art. If no argument provided, mycfetch uses first entry in arts list.  
-For convenience, you can set alias for needed art.  
+Use first argument as art name. If no arguments given or name is invalid,
+mycfetch will use first one from the `arts`
+
+For convenience, you can set alias for needed art
 
 Install
 --