Add Q-Points Calculator

[euanwm]

Is your feature request related to a problem? Please describe. Q Points is going to replace the Sinclair coefficient at some stage in the future and it would be good to have a calculator on the site.

Describe the solution you'd like Dedicated calculator with a detailed explanation of what it is and a reference to academic material.

Additional context https://huebner.shinyapps.io/Qpointsapp/

[euanwm]

Further context: https://osf.io/8x3nb/

[mountclear]

@euanwm YO! is this something i can pick up

[euanwm]

@mountclear yeah sure man, either add a new page or convert the sinclair calculator page so you can switch between sinclair and Q-point systems.