Add support for LDAP auth external secret

[feli-suco]

Hi,
With the current chart I can setup external secrets for postgresql, redis and smtp.
But I don't see any way to store the LDAP password in a external secret.
https://github.com/mastodon/chart/blob/main/values.yaml#L372-L387
Could you please advice? or add this feature.
Thanks

[timetinytim]

Apologies for taking so long to get to this.

Very much agree, this is something that we should have. I will put something together now.