Create a good landing page

[tanmaysachan]

1. Update the navigation bar. Add the osdg logo, update page links for the future.
2. Update the Header, put up a good background.
3. Modify the footer, update links for github(make it refer to this repo), remove irrelevant content.

Details on design can be discussed over individual PRs.

[deutranium]

If no one is working on this issue, can I take it up?

[tanmaysachan]

@deutranium go ahead, i'll assign it to you.

[deutranium]

@tanmaysachan I'm working on the navbar for now so i guess if someone else wants they can work on the other features too

[tanmaysachan]

@deutranium Anyone else is free to work on this as well ofc, the issue can be assigned to multiple people.
If you require assistance, or feedback, feel free to open up a draft PR.
A draft PR doesn't need to be merged, and can be used to gather constant feedback. Changes can be made along the way. Even others can contribute directly to that PR.