invoke diff in VisualStudio in the correct order

[MihailsKuzmins]

Issue: approvals/ApprovalTests.Net#549

• changed order of tempFile and targetFile
• .md files have been auto-adjusted

Now the position of the compared files is more intuitive, i.e.

• new file (received): right-hand side
• current file (approved): left-hand side
  

[SimonCropp]

so i checked the VS docs. and it seems the existing parameters are correct.

devenv /Diff SourceFile TargetFile

[MihailsKuzmins]

well, yes, but the description does not unambiguously state which file is on the left-hand side and which one is on the right-hand side

SourceFile: Required. The full path and name of the first file to be compared.
TargetFile: Required. The full path and name of the second file to be compared.

What happens if you run DiffRunner.Launch(DiffTool.VisualStudio, "received.json", "approved.json") with the existing parameters?
For me the comparison output is ok only when I swapped the parameters in VisualStudio.cs. With the existing parameters I have the problem which I described in the original issue approvals/ApprovalTests.Net#549.

[SimonCropp]

replaced by #243