doc: organize components-in-core
This PR adds 'summaries' to each argument whether (or not) a component should be in core, and uses Microsoft Style Guide based sentence structure.
New
- Standardized functionality: The component provides functionality that is standardized (such as a [Web API][]) and overlaps with existing functionality.
Old
- The component provides functionality that is standardized (such as a [Web API][]) and overlaps with existing functionality.