queries.yaml is empty

[marekaf]

README states:

The -extend.query-path command-line argument specifies a YAML file containing additional queries to run. 
Some examples are provided in [queries.yaml](https://github.com/prometheus-community/postgres_exporter/blob/master/queries.yaml).

but queries.yaml is empty.

[SuperQ]

The extended query configuration is optional, as well as deprecated. There is no need for it.

[marekaf]

That means the README can be improved to reflect that. It clearly mentions examples in a file that is empty.

[ARPABoy]

The new/non-deprecated way is poorly documented, rendering doc useless:
https://github.com/prometheus-community/postgres_exporter#adding-new-metrics

There's a Python snippet that is supposed to be used for copying table descriptions from PostgreSQL documentation, supposing that I can get that output, wheres is supposed to be copied? The main configuration file only supports auth_modules related configuration.

One basic and complete example would be great.

[sebastiansterk]

@SuperQ Some more detailed documentation about this would be really helpful.