add new page for experimental features

doc/Language/experimental.pod6

@@ -0,0 +1,28 @@
+=begin pod
+
+=TITLE Experimental features
+
+=SUBTITLE New features for brave users
+
+During Perl_6 development, new features are often made available on
+the main branch.  Eventually they may be incorpoated into the next
+version of Perl_6.  To use such features, one uses the C<experimental>
+pragma in program source code like this:
+
+=begin code
+use experimental;
+=end code
+
+Following is a list of current experimental features and a short
+description of each features's purpose or a link to more details about
+its use.  (Note: Features marked marked "[TBD]" are to be defined
+later.)
+
+=comment The following should be a table but formatting in tables is
+not yet rendered properly.
+
+=item X<B<cache>|cache> [TBD]
+
+=item X<B<pack>|pack> [TBD]
+
+=end pod