Proton: Where is the whitelist file for proton located?

[romulasry]

Feature Request

I confirm:

• [X] that I haven't found another request for this feature.
• [X] that I have checked whether there are updates for my system available that
  contain this feature already.

I would like to see the most up to date list of the whitelisted games but I am having trouble finding it. Anyone know?

Thanks in advance.

[MartinPL]

https://steamdb.info/app/891390/info/