Add DandiHub edition of read NWB file tutorial

[vijayiyer05]

Minimally modified read_demo tutorial that 1) uses dandi Python package for download and 2) bypasses MatNWB install.

Motivation

The original tutorial delayed getting to the science with initial sections focused on downloading the data and installing MatNWB. In the DandiHub configured environment, the former can be streamlined (by using the pre-installed dandi Python package) and the latter can be skipped (since MatNWB is pre-instlalled).

How to test the behavior?

1. Select the MATLAB image for the Base server option on DandiHub. 
2. Supply MathWorks credentials if prompted (not needed every time)
3. When the launcher appears, select the MATLAB desktop option
4. Open this live script (in the MatNWB tutorials folder) and select Run (▶️button) from the Live Editor tab in the desktop ribbon

The live script should run through and generate the same outpus as in the saved live script. The downloaded data should appear in the dandisets\000004 folder and is ~70MB in size.

Checklist

• [x] Have you ensured the PR description clearly describes the problem and solutions?
• [x] Have you checked to ensure that there aren't other open or previously closed Pull Requests for the same change?
• [x] If this PR fixes an issue, is the first line of the PR description fix #XX where XX is the issue number?

[vijayiyer05]

Request review by @ehennestad, following up on our recent discussion

[vijayiyer05]

Following up @ehennestad, to confirm you can see this PR