Optimising critical rendering paths

While neo.mjs is focussing on high performance apps, which often run inside envs with fast internet connections, it also should not ignore users with slow network connections.

When analysing the initial paintings inside throttled envs, I realised that it can happen that widgets try to get painted before their related CSS files got loaded. Please watch the 2 short (30s) videos so see how drastic this change is.

1. Non-optimised critical rendering paths:
   https://youtu.be/pUPLUUeuxZo

2. Optimised critical rendering paths:
   https://youtu.be/rwH1ATOgkyI

Enjoy the new version!