Testing conventions: refers to expect but uses describe

[gkiely]

In the section Testing conventions: https://www.reactnative.guide/7-testing/7.1-jest-setup.html it mentions:
"In each expect, we first mention the function name which is to be tested."

Summary
I believe this is referenced incorrectly because expect typically accepts the function to be tested.

Expected:

• The code snippet uses describe, it or test, and expect
• The conventions mention describe and it or test

Actual

• The code snipped doesn't use expect it uses describe

I would've submitted a PR for this but I'm not sure of the ideal format.

Suggestion:

describe('counter', () => {
  it('should increment the passed value', () => {
    expect(counter(1)).toBe(2);
  });
});