Update readme on build info

Author: MrOrz

README.md

@@ -9,14 +9,18 @@ We wiped-out all accidentally commited project specific files in the new repo, a
 
 To run hackfoldr on local machine, please install `docker` & `docker-compose` first, then run:
 
-```
-$ docker-compose up
+```bash
+docker-compose up
 ```
 
 This will spin up http://localhost:3000 using the latest code in the current directory.
 
 If you update package.json, you will need to rebuild the base image using:
 
+```bash
+docker-compose up --build
 ```
-$ docker-compose up --build
-```
+
+## Build
+
+Build process is part of the dev process above, thus all the files for production build will be in `_public` already.