feat(secrets): add proton pass secrets adapter

[mspori]

Proton Pass organizes secrets into vaults and items. The default attribute of each item is "password". Other attributes can be accessed by specifying them (e.g. MyItem/MyAttribute). The --from option specifies the vault path (e.g. --from MyVault)

The Proton Pass adapter does not use the --account option.

Site documentation PR: basecamp/kamal-site#191

[mspori]

Hi @djmb! I saw that you were involved in many of the secrets adapters. Any chance this one is relevant enough to be included? Also happy to hear feedback if the implementation needs improvements.
Thank you

[scmmishra]

Hey @mspori I was wondering if Kamal had support for custom adapters, it would be far easy for the maintainers as well as the users. I've proposed it in an issue here: #1765
Let me know what you think

@djmb do you think is this a good idea?