(GH-105) Update README.md to reflect changes to targeted frameworks

Author: Jericho

README.md

@@ -27,8 +27,9 @@ PM> Install-Package HttpMultipartParser
 
 ## .NET framework suport
 
-The parser was built for and tested on NET 4.6.1, NET 4.7.2, NETSTANDARD 2.0 and NET 5.0.
-Versions 2.2.4 was the last version of HttpMultipartParser that supported older .NET platforms such as NET 4.5 and NETSTANDARD 1.3.
+The parser was built for and tested on .NET 4.8, .NET standard 2.1, .NET 5.0 and .NET 6.0.
+Version 5.1.0 was the last version that supported .NET 4.6.1, NET 4.7.2 and .NET standard 2.0.
+Version 2.2.4 was the last version that supported older .NET platforms such as .NET 4.5 and .NET standard 1.3.
 
 ## Usage