Documentation: fix typos and dependencies

[achille-martin]

Fixed typos and unnecessary dependencies in Dask note

[achille-martin]

@colinsauze

[colinsauze]

I think removing the progress library takes away nice progress bars inside jupyter as things load.

[achille-martin]

Fair enough, it did not seem used, but maybe it is called implicitly somewhere?

[achille-martin]

There is a nice example on using the default progress bar here:

https://docs.dask.org/en/stable/diagnostics-distributed.html

# Progress bar with the distributed scheduler
from dask.distributed import Client, progress

client = Client()  # use dask.distributed by default

x = x.persist()  # start computation in the background
progress(x)      # watch progress

x.compute()      # convert to final result when done if desired