[io grant] Document IO::Path.succ

Author: zoffixznet

doc/Type/IO/Path.pod6

@@ -301,6 +301,18 @@ L«C<$.CWD> attribute|type/IO::Path#attribute_CWD». To stringify while
 retaining full path information use L«C<.absolute>|/routine/absolute» or
 L«C<.relative>|/routine/relative» methods.
 
+=head2 method succ
+
+Defined as:
+
+    method succ(IO::Path:D: --> IO::Path:D)
+
+Returns a new L<IO::Path> constructed from the invocant, with
+L«C<.basename>|/routine/basename» changed by calling
+L«C<Str.succ>|/type/Str#method_succ» on it.
+
+    "foo/file02.txt".IO.succ.say; # OUTPUT: «"foo/file03.txt".IO␤»
+
 =head2 method open
 
 Defined as: