feat: make the content editor focused when the reply form is opened (#104)

支持打开评论回复时，自动聚焦输入框。

/kind feature

```release-note
支持打开评论回复时，自动聚焦输入框。
```

Author: ruibaby

packages/comment-widget/src/base-form.ts

@@ -223,6 +223,10 @@ export class BaseForm extends LitElement {
     form?.reset();
   }
 
+  setFocus() {
+    this.textareaRef.value?.focus();
+  }
+
   static override styles = [
     varStyles,
     baseStyles,

packages/comment-widget/src/reply-form.ts

@@ -38,6 +38,15 @@ export class ReplyForm extends LitElement {
 
   baseFormRef: Ref<BaseForm> = createRef<BaseForm>();
 
+  override connectedCallback(): void {
+    super.connectedCallback();
+
+    setTimeout(() => {
+      this.scrollIntoView({ block: 'center', inline: 'start', behavior: 'smooth' });
+      this.baseFormRef.value?.setFocus();
+    }, 0);
+  }
+
   override render() {
     return html`<base-form ${ref(this.baseFormRef)} @submit="${this.onSubmit}"></base-form>`;
   }