Add skill overview and attributes sections to player guide; create skill overview page and JSON data for skills

_sass/_layout.scss

@@ -2,6 +2,10 @@
   font-family: BlenderProBook, sans-serif;
 }
 
+strong {
+  font-weight: 600;
+}
+
 body {
   height: 100vh;
   min-height: 100vh;