Create EN_NGHolidayStrategy.cs

[Aisha-Gama]

This pull request introduces support for Nigerian holidays in the DateTimeExtensions project. The new EN_NGHolidayStrategy class includes both fixed and movable holidays observed in Nigeria, such as:

•	New Year’s Day
•	Good Friday
•	Easter Monday
•	Workers’ Day
•	Eid al-Fitr (End of Ramadan)
•	Eid al-Adha (Festival of Sacrifice)
•	Maulid (Birth of Prophet Muhammad)

Each holiday was added as a FixedHoliday or VariableHoliday based on its observance pattern. These updates ensure Nigerian users have localized, accurate holiday data for calculations involving non-working days.

Let me know if any adjustments are required for the new holiday definitions. Looking forward to your feedback!

[joaomatossilva]

Hi, I'll gladly merge your PR. Can you fix the compilation errors?

[joaomatossilva]

I guess C# is not your natural language.
This is not a single file solution. Try to open the .sln file and use a proper IDE. You can try Jetbrains Raider or Visual Studio Community, and compile it.

Usually we don't put more than one class per file.

[Aisha-Gama]

I guess C# is not your natural language.

This is not a single file solution. Try to open the .sln file and use a proper IDE. You can try Jetbrains Raider or Visual Studio Community, and compile it.

Usually we don't put more than one class per file.

Thank you for your feedback! You’re correct; C# isn’t my primary language, and I appreciate your guidance. I’ll make sure to open the .sln file in a proper IDE like JetBrains Rider or Visual Studio Community to compile the project correctly. I also understand the convention of having one class per file and will keep that in mind moving forward. Thank you for your help!

[M4SOOM]

was this fixed?