Updated "getting started" instructions

Author: alex-golovanov

README.md

@@ -16,6 +16,11 @@ Install [yarn](https://github.com/yarnpkg/yarn) if you don't have it already:
 npm install -g yarn
 ```
 
+Then copy environment variables and edit them if necessary:
+```
+cp .env.example .env
+```
+
 Then:
 ```
 yarn install
@@ -30,6 +35,8 @@ For production builds:
 yarn run prod:start
 ```
 
+Note: pm2 must be installed to run production builds.
+
 ## Directory Structure
 ```
 ├── client                         # Client-side code