[io grant] Document role IO's new purpose

Author: zoffixznet

doc/Type/IO.pod6

@@ -4,8 +4,9 @@
 
 =SUBTITLE Input/output related routines
 
-Please note that coercion via L<Cool.IO|/type/Cool#method_IO> leads to
-L<IO::Path|/type/IO::Path>. This is the exception from the rule.
+The role provides no methods, but exists so that C<IO()> coercers, which coerce
+to L<IO::Path>, correctly type-check the resultant value. The role is done
+by L<IO::Path> and L<IO::Special>.
 
 =head1 Routines
 

doc/Type/IO/Handle.pod6

@@ -4,7 +4,7 @@
 
 =SUBTITLE Opened file or stream
 
-   class IO::Handle does IO { }
+   class IO::Handle { }
 
 =head1 Methods
 

doc/Type/IO/Socket.pod6

@@ -4,7 +4,7 @@
 
 =SUBTITLE Network socket
 
-    role IO::Socket does IO { ... }
+    role IO::Socket { ... }
 
 C<IO::Socket> contains read and write methods for sockets. It is usually used
 through L<IO::Socket::INET>.

doc/Type/IO/Special.pod6

@@ -4,6 +4,9 @@
 
 =SUBTITLE Path to Special I/O device
 
+=for code :skip-test
+class IO::Special does IO { }
+
 Used as a L«C<$.path>|/type/IO::Handle#method_path>» attribute in special
 standard input and output handles C<$*IN>, C<$*OUT> and C<$*ERR>. Provides
 abridged interface of L«C<IO::Handle>|/type/IO::Handle», mostly file tests