migrated CRA to Vite and made necessary changes

[HelloSniperMonkey]

chore(build process changed from CRA to Vite): migrated from CRA to Vite

this adresses #286

changes :

• added Vite and its dependencies to package.json
• moved index.html from public folder to root because Vite requires the index.html file to be at the root folder and changed necessary path of files accessed by index.html
• made minor changes to index.html file like adding script tag for vite to work
• changed process.env to import.meta.env at multiple places as vite uses later as opposed to former being used by CRA
• some changes were made to yarn.lock file to work with Vite