adding some stubbed CSS files

src/resources/css/elements/links.css

@@ -0,0 +1 @@
+a {}

src/resources/css/elements/pre-codes.css

@@ -0,0 +1,3 @@
+pre {}
+
+code {}

src/resources/css/elements/progress-bars.css

@@ -0,0 +1,5 @@
+.progress-bar {}
+
+.progress-arc {}
+
+.progress-ring {}