Add events page and make navbar show/hide

[hayleyw7]

Add Events Page

Description

Added events page and a few other small changes to make that work.

Note: This entire functionality of showing a proof of concept during brainstorm drafts of how the site will work/look. This is not expected to be the permanent logic used for site navigation.

https://github.com/nditcommunity/ndit-website/issues/8

Type of change

• [ ] Bug fix
• [x] New feature
• [ ] Documentation
• [ ] Infrastucture
• [ ] Other (please clarify): _____

Change log

• Added events page in html
• Added event page logic in js
• Kept precise width of theme icon
• Made all page hide/show

Testing

• Viewed and clicked all navbar headings viewing page in browser
• Checked for new console errors
• Viewed and clicked theme icon

Checklist

• [x] I have performed a self-review of my own code.
• [x] I have commented my code, particularly in hard-to-understand areas.
• [x] My changes generate no new console warnings.
• [x] I manually tested to prove my fix is effective or that my feature works.
• [x] I have assigned this PR to an owner.