Also added extra reference links

Signed-off-by: Dhruva Gole <goledhruva@gmail.com>

Dhruva Gole authored 2 years ago and Dhruva Gole committed 2 years ago

Also create index.rst inside /intro/contribution/.
Add Linux kernel (upstream) contribution guidelines.
This will help newcomers to understand in a much more
friendly and simpler manner about the process of
upstreaming.

Signed-off-by: Dhruva Gole <goledhruva@gmail.com>