Add test to show that global widgets need not use the _parameters field

editions/test/tiddlers/tests/data/globals/CustomWidgetAlt.tid

@@ -0,0 +1,23 @@
+title: Globals/CustomWidgetAlt
+description: Global shadow variable defining a custom widget, without using a _parameters field
+type: text/vnd.tiddlywiki-multiple
+tags: [[$:/tags/wiki-test-spec]]
+
+title: Output
+
+\whitespace trim
+
+<$$mywidget foo="Mahogany">
+Sycamore!
+</$$mywidget>
++
+title: $:/global/$$mywidget
+_is_widget: yes
+
+\parameters (foo:"bar")
+
+Koala! <$text text=<<foo>>/>, <$slot $name="ts-raw"/>
++
+title: ExpectedResult
+
+<p>Koala! Mahogany, Sycamore!</p>