Add Multi-Language Descriptions for 'Switch' Component and Update Message Assistant Placeholder (#2450)

### What problem does this PR solve?

_This PR addresses the need to describe the "Switch" component across
different languages and corrects a misleading description for a
placeholder message not exclusively tied to a specific assistant type.
By providing clearer and more accurate descriptions, this PR aims to
improve user understanding and usability of the Switch component and the
"Message Resume Assistant..." placeholder in a multilingual context._

### Explanation of Changes

1. **Added Descriptions for "Switch" Component**: 
- Descriptions were added for the "Switch" component in three different
locales:
- **English (EN)**: Provides a concise description of what the "Switch"
component does, focusing on its ability to evaluate conditions and
direct the flow of execution.
- **Simplified Chinese (ZH)**: Translated the English description into
Simplified Chinese to cater to users who prefer this locale.
- **Traditional Chinese (ZH-Traditional)**: Added a Traditional Chinese
version of the description to support users in regions that use
Traditional Chinese.
   
2. **Corrected "Message Resume Assistant..." to "Message the
Assistant..."**:
- Updated the description from "Message Resume Assistant..." to "Message
the Assistant..." in the English locale. This correction makes the
description more generic and accurate, reflecting the placeholder's
broader functionality, which is not limited to Resume Assistants. It now
clearly communicates that the placeholder can be used with various types
of assistants, not just those related to resumes.

### Type of change

- [ ] Bug Fix (non-breaking change which fixes an issue)
- [x] New Feature (non-breaking change which adds functionality)
- [x] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Other (please describe):

web/src/locales/zh-traditional.ts

@@ -616,6 +616,7 @@ export default {
       messageDescription:
         '此元件用於向使用者發送靜態訊息。您可以準備幾條訊息，這些訊息將隨機選擇。',
       keywordDescription: `該組件用於從用戶的問題中提取關鍵字。 Top N指定需要提取的關鍵字數量。`,
+      switchDescription: `該組件用於根據前面組件的輸出評估條件，並相應地引導執行流程。通過定義各種情況並指定操作，或在不滿足條件時採取默認操作，實現複雜的分支邏輯。`,
       wikipediaDescription: `此元件用於從 https://www.wikipedia.org/ 取得搜尋結果。通常，它作為知識庫的補充。 Top N 指定您需要調整的搜尋結果數。`,
       promptText: `請總結以下段落。注意數字，不要胡編亂造。段落如下：
 {input}