Create tutorial on linking data

[oruebel]

2) Feature Request

A couple of issues recently have asked about linking data. We have a tutorial on modular storage right now, we should extend it or add a new tutorial to describe some of the common questions we have seen on this.

E.g., #882 on linking timestaps:

with NWBHDF5IO('f2.nwb', mode='w') as io:
    ts1 = TimeSeries(name='1', data=np.ones(1000), timestamps=np.ones(1000), unit='s')
    ts2 = TimeSeries(name='2', data=np.ones(1000), timestamps=ts1, unit='s')
    f2 = nwbfile_factory()
    f2.add_acquisition(ts1)
    f2.add_acquisition(ts2)
    io.write(f2)

Or default behavior for copy vs. linking data #668 (comment)

with NWBHDF5IO('file2.nwb', mode='w', manager=manager) as io:
        io.write(nwb, link_data=False)

Problem/Use Case

Clarify documentation to describe questions that have been raised in issues.

Checklist

• Have you ensured the feature or change was not already reported ?
• Have you included a brief and descriptive title?
• Have you included a clear description of the problem you are trying to solve?
• [-] Have you included a minimal code snippet that reproduces the issue you are encountering?
• Have you checked our Contributing document?