Document in docs.pulsetile.com the Core components

[PhilBarrett]

Should be a copy and paste from React, with new code snippets.

[tony-shannon]

please consider whether to focus on this before/after Lerna migration #49

[PhilBarrett]

Quality work @BogdanScherban thankyou.

One minor change in ReSPECT plugin, it refers to the Vitalsigns API

/api/patients/{patientId}/vitalsigns

@tony-shannon can you have a brief review please, before I close off