feat: add mkdir alias to configs/alias_useful.fish that cds into the created folder

configs/alias_useful.fish

@@ -5,6 +5,11 @@
 alias mount_all='sudo $HOME/.config/fish/scripts/mount.sh'
 alias umount_all='sudo $HOME/.config/fish/scripts/umount.sh'
 
+function mkdir
+    command mkdir $argv
+    and cd -- $argv[-1]
+end
+
 ################ COMMON ALIASES ################################################
 
 alias rm='rm -r'