1119 Support method return types

Small refactor to split out logic for determining method display text and style. Updated documentation
Used regex to parse method statements in class diagrams to extract discrete elements to set display appropriately. Added tests and updated docs

cypress/integration/rendering/classDiagram.spec.js

@@ -274,4 +274,19 @@ describe('Class diagram', () => {
     );
     cy.get('svg');
   });
+
+  it('11: should render a simple class diagram with return type on method', () => {
+    imgSnapshotTest(
+      `
+    classDiagram
+      class Class10~T~ {
+        int[] id
+        test(int[] ids) bool
+        testArray() bool[]
+      }
+      `,
+      {}
+    );
+    cy.get('svg');
+  });
 });