Add a couple more images to docs (#206)

* Add service loader image to docs.

* Add connection service image.

* Fix image width

docs/design/index.md

@@ -24,6 +24,13 @@ serially.
 
 <img src='../images/msgdispatch.png' width='650px' />
 
+Messages are handled by services that register with the message processing component.  The dispatch table maps
+JSON-RPC message names to callbacks in the various services.  Currently these services are hard-coded into
+the service layer executable.  A future refactor will move to a MEF-based dynamic discovery design such as
+the below diagram illustrates.
+
+<img src='../images/serviceregistration.png' width='650px' />
+
 The below sequence diagram show an example of how the language service may process a error checking diagnostics
 workflow.  In this example the editor hosts a language service client that responds to user initiated editing events.
 The user actions are translated into a sequence of request\response pairs and one-way event notifications. 
@@ -61,6 +68,9 @@ A connection is required to work with many language service and query execution
 ([src link](https://github.com/Microsoft/sqltoolsservice/blob/dev/src/Microsoft.SqlTools.ServiceLayer/Connection/ConnectionService.cs)) 
 is the class that implements the connection management protocol.
 
+
+<img src='../images/connectionservice.png' width='600px' />
+
 ## Query Execution
 The Query Execution component provides the ability to execute SQL scripts against SQL Server instances.
 This functionality builds onto the support in System.Data to provide features batch processing support 

docs/guide/building_sqltoolsservice.md

@@ -43,7 +43,7 @@ xUnit.net .NET CLI test runner (64-bit win10-x64)
 SUMMARY: Total: 1 targets, Passed: 1, Failed: 0.
 ```
 
-### Collecting Code coverage
+### Collecting Code Coverage
 
 > Code coverage requires a SQL Server instance installed on the localhost with Integrated Authentication 
 > configured for the current user executing the test suite.