Proj4025: Remove section header

Unlike .editorconfig files, which use headers (like [*.cs]) to scope rules to specific files, .globalconfig files apply globally. Sections headers have no meaning, and should be removed.

Non-compliant

is_global = true
        
dotnet_diagnostic.CA1860.severity  = none       #  Prefer comparing 'Length' to 0 rather than using 'Any()'
dotnet_diagnostic.CS1591.severity  = suggestion # Missing XML comment for publicly visible type or member

[*.cs]
dotnet_diagnostic.IDE0001.severity = warning    # Simplify name

Compliant

is_global = true
        
dotnet_diagnostic.CA1860.severity  = none       #  Prefer comparing 'Length' to 0 rather than using 'Any()'
dotnet_diagnostic.CS1591.severity  = suggestion # Missing XML comment for publicly visible type or member

dotnet_diagnostic.IDE0001.severity = warning    # Simplify name