Created Javascript components & finished Toggle button

[RiyaTayal20]

Commit 1:

• The inline javascript code in detail.html has been moved to its own js file called tabs.js. This component can be used for other pages that require tabs.
• Another file was created (tab-init.js) to specifically invoke the details page tab-list
• Created favorite-button.js to help with making a toggle button for a favorite contact
• Made additional changes to detail.scss and detail.html to provide support for the toggle button.
• Also installed ejs dependencies which made changes to package-lock.json & package.json

Commit 2:

• Removed unnecessary comments
• Made default tab "Company" again
• Fixed logic in favorite-button.js if statement
• Fixed styling of favorite toggle button in detail.scss & detail.html

Closes #44