Include JS and 3D Math tutorials and/or references

[yaustar]

As an unspoken rule, we don’t teach the JS or math basics in the documentation as there are plenty of different sites and references we could refer them to.

However, given there are a group of our users that do come from non-JS backgrounds such as Unity3D and other languages, it could be worth highlighting some ‘gotchas’ in JS such as variable hoisting and the ‘this’ scope.