fix: Grammatical fixes for Adapter (#1783)

* Grammatical fixes

* Update adapter/README.md

Co-authored-by: Subhrodip Mohanta <hello@subho.xyz>

adapter/src/test/java/com/iluwatar/adapter/AdapterPatternTest.java

@@ -33,7 +33,7 @@ import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;
 
 /**
- * Test class
+ * Tests for the adapter pattern.
  */
 class AdapterPatternTest {
 

adapter/src/test/java/com/iluwatar/adapter/AppTest.java

@@ -33,9 +33,7 @@ import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 class AppTest {
 
   /**
-   * Issue: Add at least one assertion to this test case.
-   *
-   * Solution: Inserted assertion to check whether the execution of the main method in {@link App}
+   * Check whether the execution of the main method in {@link App}
    * throws an exception.
    */