Add tasks description and information about the project about alx-files_manager

[Davenchy]

I completely agree with your suggestion. Additionally, we could reference the issues and To-Do list for each task or feature. Let's focus on completing the mandatory tasks first to save time. After that, we can update the README.md file, as it currently contains incorrect details about our project and file structure. Depending on the size of the updated README, we can decide whether to include the task descriptions in the same file or in a new Markdown file.

• Complete mandatory tasks
• Update README file
• Add tasks detailed descriptions

[Davenchy]

We have to update the README file too.

• Add a link to the task details file.
• Update the README file to fill the template with our project details.