use head3 instead of item for getc extra text

Author: timo

doc/Type/IO/Handle.pod6

@@ -29,22 +29,22 @@ my $line = $fh.get;
 Read a single character from the input stream or return Nil. The operation will block
 for at least one character to be available, but there are a few caveats for this:
 
-=item Buffering terminals
-
-    Using getc to get a single keypress from a terminal will only work properly if
-    you've set the terminal to "unbuffered". Otherwise the terminal will wait for
-    the return key to be struck or the buffer to be filled up before perl6 gets
-    even a single byte of data.
-
-=item Waiting for potential combiners
-
-    If your handler's encoding allows combining characters to be read, perl6 will
-    wait for more data to be available before it provides a character. This means
-    that inputting an "e" followed by a combining acute will give you an e with an
-    acute rather than giving an "e" and letting the next reading function give you
-    a dangling combiner. However, it also means that when the user inputs just an
-    "e" and has no intention to also input a combining acute, your program will be
-    waiting for another keypress before the initial "e" is returned.
+=head3 Buffering terminals
+
+Using getc to get a single keypress from a terminal will only work properly if
+you've set the terminal to "unbuffered". Otherwise the terminal will wait for
+the return key to be struck or the buffer to be filled up before perl6 gets
+even a single byte of data.
+
+=head3 Waiting for potential combiners
+
+If your handler's encoding allows combining characters to be read, perl6 will
+wait for more data to be available before it provides a character. This means
+that inputting an "e" followed by a combining acute will give you an e with an
+acute rather than giving an "e" and letting the next reading function give you
+a dangling combiner. However, it also means that when the user inputs just an
+"e" and has no intention to also input a combining acute, your program will be
+waiting for another keypress before the initial "e" is returned.
 
 =head2 method eof