Add NIRx files recorded with NIRStar 15.2 with short channels and triggers

[rob-luke]

Add NIRx recordings for new file reader proposed in MNE PR.

File Generation

1. Open NIRSite 2.0

2. Add sources at T7, TP8, P01, AF2, Cz

3. Add detectors at T8, TP7, P02, AF1, FC1, CP2, CP1. FC2

4. Add short channels to T7, TP8, P01, AF2, Cz
   The screen now looks like...
   
   

5. Save and selection option to target the NIRStar application. Check all boxes

6. Close NIRSite and open NIRStar 15.2

7. Go to Configure Hardware -> Montage -> and select the montage saved above

8. Leave other options as standard. Just in case here are screen shots of all other tabs
   
   
   
   

9. Exit hardware setup and click Calibrate
   

10. Record approximately 12s of data. Send through trigger 3, then 2, the 1
    

11. Save

[rob-luke]

Once your PR is merged, ask a maintainer to cut a new release of the testing data, e.g. 0.53.

@larsoner could you please take a look at this PR and let me know if I missed any steps and need to do anything else.

[rob-luke]

Thanks, First accepted MNE PR!!