Improve Boid Flocking model to benchmark

[coderbeta1]

Changes Made:

1. Benchmark: Changed the default values and code to that of benchmark

[rht]

Merged, thank you.

[EwoutH]

Thanks for this. However, please do note that there’s a difference between the purpose of the examples and the benchmarks:

• The examples are public facing and should show best practices in Mesa modeling. This includes code cleanness and reliability.
• The benchmarks are an internal development tool, and are focused on optimizing performance, sometimes as the costs of readability or complexity.

Since both have their own, different purposes they may differ (significantly) in some cases.

In this case I find the new implementation less structured and readable.

[rht]

The one consistent with benchmark has division by N instead of by 2. This is also consistent with the implementation in https://github.com/JuliaDynamics/ABM_Framework_Comparisons, which has the fix JuliaDynamics/ABMFrameworksComparison#73.