tag multi-line methods properly

Author: coke

doc/Type/Test.pod6

@@ -192,16 +192,18 @@ of the test.
 Defined as:
 
     multi sub is-approx(Numeric $got, Numeric $expected, $desc = '')
+
     multi sub is-approx(Numeric $got, Numeric $expected, Numeric $abs-tol,$desc = '')
-    =for code
+
+=for code :method
     multi sub is-approx(Numeric $got, Numeric $expected, $desc = '',
                         Numeric :$rel-tol is required)
 
-    =for code
+=for code :method
     multi sub is-approx(Numeric $got, Numeric $expected, $desc = '',
                         Numeric :$abs-tol is required)
 
-    =for code
+=for code :method
     multi sub is-approx(Numeric $got, Numeric $expected, $desc = '',
                         Numeric :$rel-tol is required,
                         Numeric :$abs-tol is required)