UI Fixes for "Edit Your Story"

[matteoterrien]

Problem

We almost finished with users being able to edit their stories! We just want to tidy up the UI so it's not funky.

Notes

[additional considerations]

• Make sure to run git pull before any development work
• Complete your development in a new branch
• Link this issue to your PR
• Feel free to reach out if you have any questions!

Task

• Disable scrolling behind the pop-up after pressing "edit".
• Optional, but highly appreciated: Before the pop-up occurs, have the background screen scroll to the top or push the footer down. Just an idea though.