Document defaults of IO::Handle.read/readchars

Author: zoffixznet

doc/Type/IO/Handle.pod6

@@ -500,9 +500,11 @@ $fh.close;
 
 Defined as:
 
-    method read(IO::Handle:D: Int(Cool:D) $bytes --> Buf:D)
+    method read(IO::Handle:D: Int(Cool:D) $bytes = 65536 --> Buf:D)
 
 Binary reading; reads and returns up to C<$bytes> bytes from the filehandle.
+C<$bytes> defaults to an implementation-specific value (in Rakudo,
+the value of C<$*DEFAULT-READ-ELEMS>, which by default is set to C<65536>).
 This method can be called even when the handle is not
 L<in binary mode|/type/IO::Handle#method_encoding>.
 
@@ -518,10 +520,12 @@ L<in binary mode|/type/IO::Handle#method_encoding>.
 
 Defined as:
 
-    method readchars(IO::Handle:D: Int(Cool:D) $chars --> Str:D)
+    method readchars(IO::Handle:D: Int(Cool:D) $chars = 65536 --> Str:D)
 
 Reading chars; reads and returns up to C<$chars> chars (graphemes) from the
-filehandle. Attempting to call this method when the handle is
+filehandle. C<$chars> defaults to an implementation-specific value (in Rakudo,
+the value of C<$*DEFAULT-READ-ELEMS>, which by default is set to C<65536>).
+Attempting to call this method when the handle is
 L<in binary mode|/type/IO::Handle#method_encoding> will result in
 C<X::IO::BinaryMode> exception being thrown.