refactor: rename folder v2 and delete old docs

apps/docs/.gitignore

@@ -3,6 +3,8 @@
 
 # generated content
 .contentlayer
+.content-collections
+.source
 
 # test & build
 /coverage
@@ -11,9 +13,6 @@
 /build
 *.tsbuildinfo
 
-# bun
-bun.lockb
-
 # misc
 .DS_Store
 *.pem
@@ -22,10 +21,8 @@ bun.lockb
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
-.idea/*
-.idea
 
 # others
 .env*.local
 .vercel
-next-env.d.ts
+next-env.d.ts