Add clear getting started guidelines for new contributors

[ArsalaBangash]

• [ ] Make it clear to new contributors about how to get started
• [ ] Make the contributing guidelines visible to new users
• [ ] Make it clear if prerequisite knowledge is needed

[ninaricci29]

• [ ] Research content our getting started guide from DWYL: https://github.com/dwyl

[ArsalaBangash]

@milindvishnoi Your work on the CSSC contributing guide can help out here