feat(docs): reorganize documentation structure and update navigation links

docs/src/lib/shared.ts

@@ -0,0 +1,12 @@
+export const appName = '无限画布';
+export const docsRoute = '/docs';
+export const docsImageRoute = '/og/docs';
+export const docsContentRoute = '/llms.mdx/docs';
+
+// fill this with your actual GitHub info, for example:
+export const gitConfig = {
+  user: 'basketikun',
+  repo: 'infinite-canvas',
+  branch: 'main',
+  docsContentDir: 'docs/content/docs',
+};