Remove explanation of `@Ignore` from hello-world

exercises/hello-world/GETTING_STARTED.md

 $ gradle test
 ```
 
-To help you focus on one test at a time, [@Ignore](http://junit.sourceforge.net/javadoc/org/junit/Ignore.html)
-annotations have been added to every test but the first one. Any test with an `@Ignore` annotation will be skipped
-when you run the tests.
-
 ## Iterate through the tests
 
 After your first test passes, iterate on your solution, testing after each change.