Enable CAS to use customized CSS

Author: cslzchen

src/main/resources/cas-theme-default.properties

@@ -0,0 +1,4 @@
+# Use customized CSS file. For documentation, refer to Apereo CAS 6.2.8 documentation:
+# https://github.com/apereo/cas/blob/v6.2.8/docs/cas-server-documentation/ux/User-Interface-Customization-CSSJS.md
+cas.standard.css.file=/css/cas-redesigned.css
+cas.standard.js.file=/js/cas.js