docs: update .NET version from 6 to 8 (#40) [skip ci]

- Updated requirements section with .NET 8 link
- Updated footer text to reflect .NET 8
- Fixed typo in requirements header (added 'with' in footer)

Co-authored-by: Bruno Brito <bhdebrito@gmail.com>

Author: bjsneto

README.md

@@ -162,7 +162,7 @@ Actually another repositories with the same goal doesn't count stats with accura
 
 #### Requirements
 
-- [.NET 6](https://dotnet.microsoft.com/download/dotnet/6.0)
+- [.NET 8](https://dotnet.microsoft.com/download/dotnet/8.0)
 
 ### Authorization
 
@@ -201,4 +201,4 @@ And another special thank to [Sindre Sorhus](https://github.com/sindresorhus) to
 
 ---
 
-Made .NET 6 ❤️
+Made with .NET 8 ❤️