Update README-AR.md to sync the last changes

[MohamedAli00949]

Hi there,
I have some comments about the Arabic content.
First, I want to thank you for your interest in translating the Guide to Arabic.
Second, I have found some things didn't serve the need such as:

• The content is written in English but the headers are written in Arabic
• Some of the elements at Contributing to Open Source in general weren't found in the Arabic version such as Forge Your Future with Open Source and a lot of sections (Useful articles for new Open Source contributors, Using Version Control, Open Source books, Open Source contribution initiatives, and Open Source programs to participate in).

I suggest changing arabic the content and I can translate it.
Thanks in advance,