03_fibonacci: Update exercise to return "OOPS" for 0

[goran1010]

Because

Asking for the 0th Fibonacci member should return "OOPS" rather than 0.

This PR

• Fix md lint error in README.md - bare URL
• Update Instructions in README.md to tell learners to return "OOPS" if given a 0
• Update tests to reflect new instructions
• Update solution to reflect new instructions

Issue

Closes #XXXXX

Additional Information

Pull Request Requirements

• I have thoroughly read and understand The Odin Project Contributing Guide
• The title of this PR follows the location of change: brief description of change format, e.g. 01_helloWorld: Update test cases
• The Because section summarizes the reason for this PR
• The This PR section has a bullet point list describing the changes in this PR
• If this PR addresses an open issue, it is linked in the Issue section
• If this PR includes any changes that affect the solution of an exercise, I've also updated the solution in the /solutions folder

[goran1010]

Wow, somehow I had my origin remote set as the https://github.com/TheOdinProject/javascript-exercises which meant I created a branch on the main repo rather than my own fork 🤦

[mao-sz]

In advance of below