fix bad casing

Author: zoffixznet

doc/Language/phasers.pod6

@@ -190,7 +190,7 @@ Can have a return value that is provided even in later phases.
 
 =head2 X<CHECK|Phasers, CHECK>
 
-Runs at compile time, As late as possible, only runs once.
+Runs at compile time, as late as possible, only runs once.
 
 Can have a return value that is provided even in later phases.