A way to locate configurations in known locations about config HOT 3 OPEN

This depends on what a "configuration source" will be and how we will treat default configuration.
This is probably about "convention over configuration". Yet with support for custom configuration sources, this is probably only partially implementable in the spec.

from config.

If config is in a jar, it must be under a known file location e.g. meta-inf/config/ with a file name and file extension
If config is in file system, it must be under a known path.

from config.

Classpath: we need to use a known resource (such as a file name config with a supported suffix (properties, yaml)). We need to support runtimes that do not support runtime classpath scanning.

from config.