Remove Rider (idea) ignore statements from VS (#2991)

Rider has its own ignore file, so does Visual Studio. The ignore statements for Rider (idea) IDE should be removed from Visual Studio .gitignore file template.

VisualStudio.gitignore

@@ -293,10 +293,6 @@ paket-files/
 # FAKE - F# Make
 .fake/
 
-# JetBrains Rider
-.idea/
-*.sln.iml
-
 # CodeRush personal settings
 .cr/personal