Add an alternate theme

No UI for switching themes yet, try these two commands in the console:

`$tw.wiki.addTiddler({title:"$:/theme",
text:"$:/themes/tiddlywiki/starlight"})`

and

`$tw.wiki.addTiddler({title:"$:/theme",
text:"$:/themes/tiddlywiki/snowwhite"})`

editions/tw5.com/tiddlywiki.info

@@ -3,6 +3,7 @@
 		"tiddlywiki/fullscreen"
 	],
 	"themes": [
-		"tiddlywiki/snowwhite"
+		"tiddlywiki/snowwhite",
+		"tiddlywiki/starlight"
 	]
 }

themes/tiddlywiki/starlight/plugin.info

@@ -0,0 +1,9 @@
+{
+	"title": "$:/themes/tiddlywiki/starlight",
+	"description": "A simple, dark layout",
+	"author": "JeremyRuston",
+	"version": "0.0.0",
+	"core-version": ">=5.0.0",
+	"plugin-type": "theme",
+	"dependents": ["$:/themes/tiddlywiki/snowwhite"]
+}

themes/tiddlywiki/starlight/styles.tid

@@ -0,0 +1,35 @@
+title: $:/themes/tiddlywiki/starlight/styles.tid
+tags: [[$:/tags/stylesheet]]
+
+\rules only filteredtranscludeinline transcludeinline macrodef macrocallinline
+\define border-radius(radius)
+```
+  -webkit-border-radius: $radius$;
+     -moz-border-radius: $radius$;
+          border-radius: $radius$;
+```
+\end
+\define box-shadow(shadow)
+```
+  -webkit-box-shadow: $shadow$;
+     -moz-box-shadow: $shadow$;
+          box-shadow: $shadow$;
+```
+\end
+\define background-linear-gradient(gradient)
+```
+background-image: linear-gradient($gradient$);
+background-image: -o-linear-gradient($gradient$);
+background-image: -moz-linear-gradient($gradient$);
+background-image: -webkit-linear-gradient($gradient$);
+background-image: -ms-linear-gradient($gradient$);
+```
+\end
+
+/*
+Placeholder for a more thorough refinement of Snow White
+*/
+
+html body {
+	font-family: "Georgia", "Times";
+}