docs: 引入 Fumadocs

ci: set up github actions

docs/content/docs/openapi/.gitignore

@@ -0,0 +1 @@
+(generated)/

docs/content/docs/openapi/index.mdx

@@ -0,0 +1,4 @@
+---
+title: API 概览
+description: Open API 接口文档
+---

docs/content/docs/openapi/meta.json

@@ -0,0 +1,4 @@
+{
+  "pages": ["index", "...(generated)"],
+  "root": true
+}