Clarify use of the '$?DISTRIBUTION.ver' (and '.content') methods

+ Add examples to accompany the descriptions

Author: tbrowder

doc/Language/variables.rakudoc

@@ -1487,12 +1487,32 @@ unit module MyFoo;
 
 sub module-version {
     say "MyFoo is version:";
-    say $?DISTRIBUTION.meta<ver>;
+    say $?DISTRIBUTION.meta<ver>; # OUTPUT: «0.0.1␤»
 }
+=end code
+
+The C<.meta> method currently has hash keys of C<ver>, C<auth>, and C<api>,
+
+The C<.content> method provides access to files in the distribution
+when provided with the relative path from the distribution's top-level
+directory.
 
+=begin code :solo
 sub module-source {
     say "MyFoo source code:";
     say $?DISTRIBUTION.content('lib/MyFoo.rakumod');
+    # OUTPUT: «IO::Handle<"lib/MyFoo.rakumod".IO>(closed)␤»
+}
+=end code
+
+Note the output for the C<content> example is a B<closed> filehandle.
+To actually use the file's content, the user can extract it as a string
+in another routine in the same module:
+
+=begin code :solo
+sub get-file-content {
+    say $?DISTRIBUTION.content('lib/MyFoo.rakumod').open.slurp;
+    # OUTPUT: «unit module MyFoo;␤»
 }
 =end code