hs.timer: fix typo

Author: Habbie

extensions/timer/init.lua

@@ -3,7 +3,7 @@
 --- Execute functions with various timing rules
 ---
 --- **NOTE**: timers use NSTimer internally, which will be paused when computers sleep.
---- Especially, repeating timers won't be triggered at the specificed time when there are sleeps in between.
+--- Especially, repeating timers won't be triggered at the specified time when there are sleeps in between.
 --- The workaround is to prevent system from sleeping, configured in Energy Saver in System Preferences.
 
 local module = require("hs.timer.internal")