New document (#5299)

* add new doc (#5175)

Co-authored-by: dreamer6680 <146868355@qq.com>

* Test docs (#5235)

* fix: change the page of doc

* chore: add new dependencies, update global styles/layout, optimize docs, add Feishu & GitHub icons, update API examples

* fix: docs/index 404 not found

* Update environment variable names, optimize styles, add new API routes, fix component styles, adjust documentation, and update GitHub and Feishu icons

* update readme

* feat: add a linkfastgpt compontent

* feat: update new doc

* fix:remove unuse page and redirect homepage to docs (#5288)

* fix：remove some unuse doc

* fix: redirect homepage to doc

* git ignore

* fix:navbar to index (#5295)

* sidbar

* fix: navtab unlight (#5298)

* doc

---------

Co-authored-by: dreamer6680 <1468683855@qq.com>
Co-authored-by: dreamer6680 <146868355@qq.com>

document/content/docs/introduction/development/upgrading/42.mdx

@@ -0,0 +1,17 @@
+---
+title: 升级到 V4.2
+description: FastGPT 从旧版本升级到 V4.2 操作指南
+---
+
+99.9%用户不影响，升级 4.2 主要是修改了配置文件中 QAModel 的格式。从原先的数组改成对象：
+
+```json
+"QAModel": {
+    "model": "gpt-3.5-turbo-16k",
+    "name": "GPT35-16k",
+    "maxToken": 16000,
+    "price": 0
+}
+```
+
+改动目的是，我们认为不需要留有选择余地，选择一个最合适的模型去进行任务即可。