Add Phantom Explanation section

[pvillacorta]

Explanations: Add "Phantom" section, with the following subsections:

• Phantom structure
• Motion: by the moment, SimpleMotion and simple motion types
• .phantom file format

[pvillacorta]

AbstractMotion:

• struct NoMotion
• struct MotionList (The same as an AbstractArray{Motion} but we didn't use arrays, because ... ? we will need to discuss this in the paper)
  • struct Motion (This one makes sense)
    • Action <: AbstractAction
    • TimeSpan <: AbstractTimeSpan
    • SpinSpan <: AbstractSpinSpan (Is the user meant to extend this one?)

Is it like this?

If I don't want to define a list, can I just define obj.motion = Translate(...)?

What function must I define to generate a new AbstractMotion/AbstractAction/...?

If I want to define my new custom motion, should create a new AbstractAction or a new AbstractMotion?

Is ECG triggering possible? #73

Commented by @cncastillo