Intro to Flexbox lesson: Remove rogue </span> text

[SerbanUntu]

The tag after the first image in the lesson was separated by two newlines, causing it to be displayed as a paragraph of text in the browser, so I removed the two newlines.

Because

The space between the link to the image and the tag afterwards was too large, it caused the tag to be interpreted as a separate paragraph, leading to the visual bug.

This is a screenshot of the part of the lesson in which the visual bug occurs:

This PR

• Removes the two newlines before the tag after the link to the first image in the lesson to remove the </span> text from the page.

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