performance of the animations

[jo-pol]

Compare the speed of loading the page and completing the animation with or without the optimizations.

• [x] Try the nets page without the decorative (but out of sight) bobbins and start markers. Either add an option to the Scala method to omit them, or filter them out in JavaScript before starting the animation. Tried but it did not make a difference.
• [x] A quick win (but less fluent) is skipping steps of the animation. https://github.com/jo-pol/GroundForge/blob/0fbbfcbc/docs/js/nets.js#L142
• [ ] a better balance of the forces might gain more https://github.com/d-bl/GroundForge/blob/fdfb1dd60126080062c02e00f850be824db7b355/docs/js/nets.js#L144-L154 https://devdocs.io/d3~4-force
• [x] The animation cools down with less steps with the now explicit alphaDecay with a larger value than the default.