chore: update documentation

Author: cal-smith

src/modal/modal.component.ts

@@ -24,7 +24,7 @@ import { cycleTabs, getFocusElementList } from "./../common/tab.service";
 /**
  * Component to create modals for presenting content.
  *
- * Using a modal in your application requires `ibm-modal-placeholder` which would generally be
+ * Using a modal in your application requires `ibm-placeholder` which would generally be
  * placed near the end of your app component template (app.component.ts or app.component.html) as:
  *
 ```html
@@ -68,7 +68,7 @@ export class SampleModal extends BaseModal {
 	selector: "app-modal-demo",
 	template: `
 				<button ibmButton="primary" (click)="openModal('drill')">Drill-down modal</button>
-				<ibm-modal-placeholder></ibm-modal-placeholder>`
+				<ibm-placeholder></ibm-placeholder>`
 })
 export class ModalDemo {
 	openModal() {