Update Introduction.md

Line 24:
    A) The change of case from .Net to .NET in #163 broke the link on this line.
    B) Added an Oxford comma after "Interop" to match the format of line 25. (An alternative fix, of course, would be to leave this as-is and remove the Oxford comma on line 25; it all depends on your stance regarding this hotly-debated punctuation mark. ☺ )

Author: Nevember

Best-Practices/Introduction.md

@@ -21,5 +21,5 @@ One final note about these Best Practices: the perspective of these guidelines h
 - [Error Handling](Error-Handling.md)
 - [Performance](Performance.md)
 - [Security](Security.md)
-- [Language, Interop and .Net](Language-Interop-and-.Net.md)
+- [Language, Interop, and .NET](Language-Interop-and-.NET.md)
 - [Metadata, Versioning, and Packaging](Metadata-Versioning-and-Packaging.md)