Sales

[ibilalkayy]

Ahoy matey!

Thank ye for considering to contribute to our book project. Before ye submit your pull request, please make sure to check the following:

• [x] Your changes follow the book's style and conventions
• [ ] Your changes have been thoroughly reviewed and do not introduce any errors
• [ ] You have added appropriate documentation for your changes (if necessary)

Description of changes:

Added the sales content in the sales file

Issue(s) closed:

[List the issue(s) that this pull request resolves, if applicable]

Thanks for your contribution! We'll review your changes as soon as we can.

Yarrrr!