use environment variable for connection string on config file

[febridev]

hi
I have mention from security team about connection string at sql_exporter.yml is explicit, how to make username and password on connection string is set from variable environment
because we can't put explicitly on that's config.

[burningalchemist]

Hi @febridev , please have a look at this discussion topic: #444 (comment)

I'll include the section in the documentation 🙂👍

[febridev]

thank you very much