Fix grammatical error

[Dizzy99602]

Because

There was grammatical error in one of the file.

This PR

Added word "has" which was missing at one line in the databases_and_sql.md file.

Issue

Closes #XXXXX

Additional Information

Pull Request Requirements

• I have thoroughly read and understand The Odin Project curriculum contributing guide
• The title of this PR follows the location of change: brief description of change format, e.g. Intro to HTML and CSS lesson: Fix link text
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If any lesson files are included in this PR, they have been previewed with the Markdown preview tool to ensure it is formatted correctly
• If any lesson files are included in this PR, they follow the Layout Style Guide

[ManonLef]

Hi and thanks for contributing! That particular sentence was actually correct as it was. "That's been stored" means "That has been stored".

It seems there were a lot of spacing issues in this lesson which you or your linter has also caught. However, as you can see in the files here our linter flagged a few changes that you have introduced that are not according to our style guide. Would you like to make this lesson adhere to our style guide and revert the grammar change, or should I close this for now?