Fix typo in JestObjectAPI.md (#5559)

* Update JestObjectAPI.md

small typo :)

* Update JestObjectAPI.md

docs/JestObjectAPI.md

@@ -158,7 +158,7 @@ as well as all the modules that it imports._
 
 Modules that are mocked with `jest.mock` are mocked only for the file that calls
 `jest.mock`. Another file that imports the module will get the original
-implementation even if run after the test file that mocks the module.
+implementation even if it runs after the test file that mocks the module.
 
 Returns the `jest` object for chaining.