Preventing textarea field from being resized horizontally

[jasonnrosa]

Types of change

• [X] Bug fix (change which fixes an issue)
• [ ] Enhancement (change which improves upon an existing feature)
• [ ] New feature (change which adds new functionality)

Description

The textarea field could previously be resized horizontally which didn't create a good user experience and could lead to responsiveness issues. I've set resize: vertical; on the textarea field to combat this.

Relevant links

Example video after fix: https://www.loom.com/share/dad765647762421a82f55830dbc36f0e Fixes #426

Checklist

• [X] I have read the CONTRIBUTING document.
• [X] My code follows the style guide requirements.
• [X] I have thoroughly tested my change.

People to notify CC: @TheWebTech and @ajlaporte