Update compared-to-approvaltests.md (#476)

1. Fixed typo
2. Added some extra pieces of supporting information 

Followed the instructions on an upgrade project, everything makes sense, no problems, whole process was completed in under an hour.

Added extra info, as if you are specifically setting out to upgrade, you might not have absorbed everything in the main docs.

docs/compared-to-approvaltests.md

@@ -71,10 +71,11 @@ In ApprovalTests both these features are opt-in through attributes.
 
 This is a work-in-progress, to contribute more information submit a Pull Request.
 
-  * Choose an [approach to snapshot management](https://github.com/VerifyTests/Verify#snapshot-management).
+  * Choose an [approach to snapshot management](https://github.com/VerifyTests/Verify#snapshot-management) (default = clipboard and diff tool) 
+  * Be aware of the [usage notes](https://github.com/VerifyTests/Verify#usage) for your specific test framework
   * Remove all `ApprovalTests*` NuGets.
   * Add a reference to the specific test framework variant of Verify ([Verify.Xunit](https://www.nuget.org/packages/Verify.Xunit/)/[Verify.NUnit](https://www.nuget.org/packages/Verify.NUnit/)/[Verify.Expecto](https://www.nuget.org/packages/Verify.Expecto/)/[Verify.MSTest](https://www.nuget.org/packages/Verify.MSTest/)).
-  * Add the [Verify.ApprovalTestsTransition](https://www.nuget.org/packages/Verify.ApprovalTestsTransition/) NuGet. This NuGet contains signatures for the commonly used ApprocalTests APIs. These APIs a attributed with `[Obsolete]` that point to the alternative APIs and/or documentation. This NuGet is a work-in-progress, submit a PR is more APIs are required.
+  * Add the [Verify.ApprovalTestsTransition](https://www.nuget.org/packages/Verify.ApprovalTestsTransition/) NuGet. This NuGet contains signatures for the commonly used ApprovalTests APIs. These APIs a attributed with `[Obsolete]` that point to the alternative APIs and/or documentation. This NuGet is a work-in-progress, submit a PR is more APIs are required.
   * Fix all obsoletes.
   * Remove the Verify.ApprovalTestsTransition NuGet.
   * Delete all `*.approved.*` files.