Update docs to newer style.
Update docs to newer style.

Add build and npm badges.

jg3526/multer,dustin-H/multer,mixxen/multer,ramanujadasu/multer,expressjs/multer,xixilive/multer,kangkot/multer,kylev/multer,jacobtomlinson/multer,ACT1GMR/multer,wowzzangga/multer,hwqin/multer,zhaoshiling1017/multer,tchungdojo/multer