Change issue label for new comers in README

[quettabit]

JIRA Ticket link:

For Reviewer:

• Do acceptance tests properly cover AC?
• Do acceptance tests match real user behaviour?
• Think about how you would have solved the problem:
  • Look for abstractions.
  • Think like an adversary, but be nice about it.
  • Think about libraries or existing product code.
  • Does the change add compile-time or run-time dependencies (especially between sub-projects)?
• Does the PR only cover 1 subtask, and no more than that
• Critique data and distribution of features for acceptance tests
• Has implementation caused unforeseen backwards compatibility issues?

Checklist for pull request:

• [] All unit tests pass
• [] All examples pass
• [] All integration tests pass
• [] All acceptance tests pass
• [] Acceptance tests that fulfill AC for ticket should be created and pass
• [] Have tested both remote and local deployment types
• [] All necessary documentation and READMEs have been updated
• [] Pick realistic type of data (not large, but a good distribution of features) for acceptance tests
• [] No breaking changes to backwards compatibility

[quettabit]

In the list of issues, I don't see any label named as first-timers-only. The closest that I could see is good first issue. I suspect both mean the same. Hence, the change.