[DEV] Update documentation to describe how data is parsed with /Inventory/RedfishEndpoints

[davidallendj]

There is currently no SMD documentation that mentions how inventory data can be included in the HTTP request JSON body to populate certain data structures. The documentation should be updated to describe how to submit data in the request, how it gets parsed (at least to some degree), and what objects get created and inserted into the database. Having good documentation here will likely be very important later on if we decided to expand the parsing capabilities to create more structures specifically using the data from tools like magellan.

• Describe the HTTP request JSON structure
• Describe the parsing process in some detail
• Describe what is being created and inserted