Convey that interleaving is not the same as concurrency

Interleaving enumeration of multiple queries (i.e. alternating operations that initiate the execution of query and/or read each individual element of the results across multiple queries) is not the same as concurrent access because the DbContext can maintain independent state for each one the queries being executed and boundaries of the operations never overlap.

Whether this is supported ultimately depends on whether the underlying database connection supports MARS.

---
#### Document Details

⚠ *Do not edit this section. It is required for docs.microsoft.com ➟ GitHub issue linking.*

* ID: a47bf610-692d-9d40-d85f-aec1e2a87a07
* Version Independent ID: 3c94634a-4b17-bc13-7436-0c61aea03ab6
* Content: [Configuring a DbContext - EF Core](https://docs.microsoft.com/en-us/ef/core/miscellaneous/configuring-dbcontext)
* Content Source: [entity-framework/core/miscellaneous/configuring-dbcontext.md](https://github.com/aspnet/EntityFramework.Docs/blob/master/entity-framework/core/miscellaneous/configuring-dbcontext.md)
* Product: **entity-framework**
* Technology: **entity-framework-core**
* GitHub Login: @rowanmiller
* Microsoft Alias: **divega**