fix invalid Javadoc

Seems like IntelliJ understands this Javadoc, but the javadoc tool does not. I have changed it back to the usual syntax we use (even though it is really annoying / ugly, in particular with @literal taking up an extra space).

Signed-off-by: Peter Gafert <peter.gafert@tngtech.com>

archunit-junit/src/api/java/com/tngtech/archunit/junit/ArchTests.java

@@ -21,33 +21,33 @@
 
 /**
  * Includes all {@code @ArchTest} annotated members of another class into this ArchUnit test. For example
- * <pre>{@code
+ * <pre><code>
  * class MyArchRuleSuite1 {
- *     @ArchTest
+ *    {@literal @}ArchTest
  *     static final ArchRule suite1Rule1 = classes()...
  *
- *     @ArchTest
+ *    {@literal @}ArchTest
  *     static void suite1Rule2(JavaClasses classes) {
  *         // ...
  *     }
  * }
  *
  * class MyArchRuleSuite2 {
- *     @ArchTest
+ *    {@literal @}ArchTest
  *     static final ArchRule suite2Rule1 = classes()...
  * }
  *
- * @AnalyzeClasses(..)
+ *{@literal @}AnalyzeClasses(..)
  * class MyArchitectureTest {
- *     // includes all @ArchTest members from MyArchRuleSuite1
- *     @ArchTest
+ *     // includes all{@literal @}ArchTest members from MyArchRuleSuite1
+ *    {@literal @}ArchTest
  *     static final ArchTests includedRules1 = ArchTests.in(MyArchRuleSuite1.class);
  *
- *     // includes all @ArchTest members from MyArchRuleSuite2
- *     @ArchTest
+ *     // includes all{@literal @}ArchTest members from MyArchRuleSuite2
+ *    {@literal @}ArchTest
  *     static final ArchTests includedRules2 = ArchTests.in(MyArchRuleSuite2.class);
  * }
- * }</pre>
+ * </code></pre>
  */
 public final class ArchTests {
     private final Class<?> definitionLocation;