contributing.md file edited and code_of_conduct.md file added

[KaganCanSit]

Greetings,
While contributing to the project, it is sometimes not possible to report mistakes and combine requests in the right way with instant decisions. It is also necessary to pay attention to the rules of respect. I think the existence of the "CODE OF CONDUCT.md" file is a good reminder of respect and love, so I wanted to add it.

Note, since you do not have an e-mail address in your contact information, I indicated your Linkedin address.

If there is something you want me to edit, let me know in the comments. I will try to take a look as soon as possible.
Best regards.

[KaganCanSit]

It's been almost two years since the development here. It seems simple, but I don't remember what I was thinking. For this reason, I am closing the branch.
Best regards.