feat(main): Add base theme: This is the falcon theme out of the box.

This is falcon v3.1.2

_dev/css/theme/components/lazyload/_index.scss

@@ -0,0 +1 @@
+@import "lazyload";

_dev/css/theme/components/lazyload/_lazyload.scss

@@ -0,0 +1,5 @@
+img.lazyload {
+  &:not(.loaded) {
+    background: $gray-200;
+  }
+}