feat: creating menu bar component

[celinechoiii]

🍞 What's new in this PR

🥐 Description

• added an expanding menu bar component that is to be used throughout the app
• added pomegranate color to the global styles
• updated the background color of the app

🥖 Screenshots

🥪 How to review

• use ExpandingMenu instead of menu icon svg in the activeEvents/page.tsx file
• play around with it! see how the transitions are
• check mobile screen as well

🥧 Next steps

• add routing to the nav bars
• might need to create a layout component to ensure that menu bar only appears for certain pages

🥞 Relevant links

🥨 Online sources

🥯 Related PRs

CC: @celinechoiii