Apply suggestions from code review

Co-authored-by: Genevieve Warren <[email protected]>

Author: tarekgh

xml/System.Text/CodePagesEncodingProvider.xml

@@ -75,14 +75,14 @@
 
  After an <xref:System.Text.EncodingProvider> object is registered, the encodings that it supports are available by calling the overloads of <xref:System.Text.Encoding.GetEncoding%2A?displayProperty=nameWithType>; you should not call the <xref:System.Text.EncodingProvider.GetEncoding%2A?displayProperty=nameWithType> overloads.
 
-## Impact on Default Encoding Behavior
+### Impact on default encoding behavior
 
-Registering <xref:System.Text.CodePagesEncodingProvider> also affects the behavior of <xref:System.Text.Encoding.GetEncoding(System.Int32)> when called with a `codepage` argument of `0`:
+Registering <xref:System.Text.CodePagesEncodingProvider> also affects the behavior of <xref:System.Text.Encoding.GetEncoding(System.Int32)> when called with a `codepage` argument of `0` in .NET (Core):
 
-- **On Windows**: Returns the encoding that matches the system's active code page, which is the same behavior as in .NET Framework.
-- **On non-Windows platforms**: Still returns UTF-8, maintaining cross-platform consistency.
+- On Windows, `GetEncoding(0)` returns the encoding that matches the system's active code page, which is the same behavior as in .NET Framework.
+- On non-Windows platforms, `GetEncoding(0)` returns UTF-8, maintaining cross-platform consistency.
 
-Without any encoding provider registered, <xref:System.Text.Encoding.GetEncoding(System.Int32)> with `codepage` 0 returns UTF-8 on all platforms in .NET Core and later versions.
+When no encoding provider is registered, `GetEncoding(0)` returns UTF-8 on all platforms in .NET Core and later versions.
 
  ]]></format>
     </remarks>