zsh:alias:feh: Add --start-at flag

I found this in feh's .desktop file and liked the idea:

With `--start-at` feh will load all files from the directory of the
given file and start the filelist at the given one.

This of course breaks easily if I want to pass more flags before the
file argument, but is easily fixed by first specifying the argument to
`--start-at` and continuing with the rest. I also rarely use any flag
besides the one already defined in the alias.

.config/zsh/zshrc.d/30-alias.zsh

@@ -189,7 +189,7 @@ fi
 		add_flags rm -I
 	add_flags mkdir -p
 	add_flags lsblk -o NAME,LABEL,FSTYPE,SIZE,FSAVAIL,MOUNTPOINT
-	add_flags feh --scale-down --image-bg "'#898e8c'"
+	add_flags feh --scale-down --image-bg "'#898e8c'" --start-at
 	# Use multiple jobs when making
 	add_flags make -j
 	# Bulk renaming with (almost) all files and directly modifying the