Add Customizations.

- Add PrismJS dependencies (baked-in)
- Add Ko-fi button (in-line)
- Bump dependencies to fix inability to build.
- Concatenate *.css into single source.css.

gulpfile.js

@@ -45,7 +45,10 @@ function hbs(done) {
 
 function css(done) {
     pump([
-        src('assets/css/screen.css', {sourcemaps: true}),
+        src([
+            'assets/css/*.css'
+        ], {sourcemaps: true}),
+        concat('source.css'),
         postcss([
             easyimport,
             autoprefixer(),