[docs] Improve movie dataset

[flaviendelangle]

I added some movies to have more interesting results for the aggregation.

I will probably spend some time trying to generate a similar dataset automatically to go up to 500 movies.

[mui-bot]

These are the results for the performance tests:

Test case	Unit	Min	Max	Median	Mean	σ
Filter 100k rows	ms	245.3	509.2	354.1	354.32	100.988
Sort 100k rows	ms	485.4	878.8	721.3	714.82	134.314
Select 100k rows	ms	113.9	191.2	141.9	145.84	25.793
Deselect 100k rows	ms	99.4	227.6	196.4	165.24	45.454

Generated by 🚫 dangerJS against bb9f7ef

[alexfauquette]

What do you want to do with imbdRating data?

[flaviendelangle]

What do you want to do with imbdRating data?

In the aggregation it's the example for aggregation on a cell with a custom renderer (the Rating component).
I'll probably add it to regular grouping demo later, as it creates more good-looking grids with some color.