Java: add blank lines to qldocs

Author: Jami Cogswell

java/ql/lib/semmle/code/java/UnitTests.qll

@@ -127,10 +127,12 @@ class JUnitJupiterTestMethod extends Method {
 
 /**
  * A JUnit 5 test method.
+ *
  * A test method is defined by JUnit as "any instance method
  * that is directly annotated or meta-annotated with `@Test`,
  * `@RepeatedTest`, `@ParameterizedTest`, `@TestFactory`, or
  * `@TestTemplate`."
+ *
  * See https://junit.org/junit5/docs/current/user-guide/#writing-tests-definitions
  */
 class JUnit5TestMethod extends Method {
@@ -147,8 +149,10 @@ class JUnit5TestMethod extends Method {
 
 /**
  * A JUnit 5 test class.
+ *
  * A test class must contain at least one test method, and
  * cannot be abstract.
+ *
  * See https://junit.org/junit5/docs/current/user-guide/#writing-tests-definitions
  */
 class JUnit5TestClass extends Class {