[io grant] Expand docs for $*HOME and $*TMPDIR

Author: zoffixznet

doc/Language/variables.pod6

@@ -1126,13 +1126,15 @@ X<|$*SPEC>X<|$*TMPDIR>X<|$*THREAD>X<|$*SCHEDULER>
                       | string and the numeric group id if treated as a number.
     ------------------+--------------------------------------------
     $*HOME            | An L<IO::Path> object representing the "home directory"
-                      | of the user that is running the program.  If the
-                      | "home directory" cannot be determined it will be L<Any>
+                      | of the user that is running the program. Uses
+                      |  C«%*ENV<HOME>» if set. On Windows, uses
+                      |  C«%*ENV<HOMEDRIVE> ~ %*ENV<HOMEPATH>». If the
+                      | home directory cannot be determined, it will be L<Any>
     ------------------+--------------------------------------------
     $*SPEC            | The appropriate L<IO::Spec> sub-class for the platform that
                       | the program is running on.
     ------------------+--------------------------------------------
-    $*TMPDIR          | An L<IO::Path> object representing the "system temporary directory"
+    $*TMPDIR          | An L<IO::Path> object representing the "system temporary directory" as determined by L«C<.tmpdir IO::Spec::* method|/routine/tmpdir»
     ------------------+--------------------------------------------
     $*TOLERANCE       | Used by the C<=~=> operator, and any operations that depend on it, to
                       | decide if two values are approximately equal. Defaults to 1e-15.