Fix alignment of buttons on readme only preference

What does this MR do and why?

Fix alignment of buttons on overview page

What does this MR not do?

Fix the spacing of the action buttons. We're using gl-gap-3 but a lot of empty divs are rendering, causing larger gaps than necessary. Will look into that separately

Screenshots or screen recordings

Before	After

How to set up and validate locally

• Enable :project_overview_reorg
• User preferences > Project overview content > Readme
• Go to project overview

💬 Feedback: Project overview page (#434684 - closed)

✂️ UX Paper Cuts 16.7 → Project page (#430244 - closed)

✂️ UX Paper Cuts 16.8 → Accessibility (#424396 - closed)