'lib/completion.zsh: Solve typos'

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

lib/completion.zsh

@@ -5,7 +5,7 @@ WORDCHARS=''
 
 unsetopt menu_complete   # do not autoselect the first completion entry
 unsetopt flowcontrol
-setopt auto_menu         # show completion menu on succesive tab press
+setopt auto_menu         # show completion menu on successive tab press
 setopt complete_in_word
 setopt always_to_end