chore: add mention of implements if a class implments an interface

Author: gituser12981u2

p3-program-linting/src/main/java/BlankPrintlnCheck.java

@@ -9,6 +9,9 @@
  * <p>
  * This check enforces the use of {@code System.out.println()} instead of
  * printing an empty string.
+ *
+ * <p>
+ * Implements {@link Check}.
  */
 public final class BlankPrintlnCheck implements Check {
     /**

p3-program-linting/src/main/java/BreakCheck.java

@@ -10,6 +10,8 @@
  * {@code //}) is considered a violation. Content appearing after {@code //} is
  * ignored.
  *
+ * <p>
+ * Implements {@link Check}.
  */
 public final class BreakCheck implements Check {
     /**

p3-program-linting/src/main/java/LongLineCheck.java

@@ -8,6 +8,9 @@
  *
  * <p>
  * Lines longer than 100 {@code Characters} are considered a violation.
+ *
+ * <p>
+ * Implements {@link Check}.
  */
 public final class LongLineCheck implements Check {
     /**