Add contributing file

[mor39a]

Context of Contribution

• Bug Fix
• Refactoring
• New Feature
• Others

Summary of the Proposal

Add the contributing file

Reason for the new feature

Clarify and centralize the guidelines for contributing to the project.

Checklist

• This PR does not contain commits of multiple contexts.
• Code follows proper indentation and naming conventions.
• Implemented using only APIs that can be submitted to the Microsoft Store.
• Works correctly in both dark theme and light theme.
• Works correctly on any device.

[Kyome22]

@mor39a Thank you for creating the guidelines. The content looks mostly good.
Regarding the coding style, I would like to introduce a Linter and Formatter in the future.

[mor39a]

Regarding the coding style, I would like to introduce a Linter and Formatter in the future.

Which linter and formatter do you have in mind?

[Kyome22]

LGTM

[Kyome22]

Regarding the coding style, I would like to introduce a Linter and Formatter in the future.

Which linter and formatter do you have in mind?

@mor39a
I wasn't aware of the de facto standard for Linters in the Visual Studio and C# environment, but after looking into it, it seems that there are built-in features like EditorConfig and "dotnet format".

Let's discuss the Linter and Formatter in an Issue. → #283