[DOCS] Removing discontinued platforms.

[HarikalarKutusu]

Topic of request
What topic does this documentation request concern?


Removing discontinued platforms.

Kind of request

If this is a request to change existing documentation, what needs to be changed?


Both Mozilla Deepspech and Coqui STT are no more. I think they should be removed from the list at the bottom of the home page.
Alternatively, they could be moved elsewhere with a marking saying they are "discontinued".

(Probably it will be nice to include the HF & dataset link there, but this would be a managerial decision...)