config structure - rename details to something like instances

[janaka]

The config file is a key interface with dev users using anything build on top of CDF. Therefore it's important to make it as intuitive as possible. We can only go so far at the CDF level given it's lower later hence quite generalised inherently. But there's probably a little room for improvement.

details is the name of the config collection each instance of a given component or service construct type. details doesn't intuitively suggest that this section contains the config for instances.

Propose renaming details to instances.

[janaka]

As discussed change from details to entries as this is more generic while better communicating that one can have N number.