docs: add documentation for standing up server with pg to README

Makefile

@@ -1,2 +1,25 @@
-dev:
+# These targets were made with unix in mind.  If you are not on unix, feel free to update for support.
+-include .env
+.DEFAULT_GOAL = dev
+
+env:
+	@export DB_PORT=${DB_PORT}
+	@export DB_USER=${DB_USER}
+	@export DB_PASSWORD=${DB_PASSWORD}
+	@export DB_NAME=${DB_NAME}
+	@echo 'db environment updated'
+
+dev: env
 	@yarn run dev
+
+db-migrate: env
+	bin/rails db:migrate
+
+db-seed: env
+	bin/rails db:seed
+
+init: env
+	@command -v yarn > /dev/null 2>&1 || { echo >&2 "please install yarn first"; exit 1; }
+	bin/rails db:setup
+	bin/rails db:migrate
+	bin/rails db:seed

README.md

@@ -1,4 +1,44 @@
 # flextensions
 Back end/API for UC Berkeley EECS "Flextensions" software
 
-[![Maintainability](https://api.codeclimate.com/v1/badges/8d99ec9a1784ddba34ac/maintainability)](https://codeclimate.com/github/cs169/flextensions/maintainability) [![Test Coverage](https://api.codeclimate.com/v1/badges/8d99ec9a1784ddba34ac/test_coverage)](https://codeclimate.com/github/cs169/flextensions/test_coverage)
+[![Maintainability](https://api.codeclimate.com/v1/badges/8d99ec9a1784ddba34ac/maintainability)](https://codeclimate.com/github/cs169/flextensions/maintainability) [![Test Coverage](https://api.codeclimate.com/v1/badges/8d99ec9a1784ddba34ac/test_coverage)](https://codeclimate.com/github/cs169/flextensions/test_coverage)
+
+## Installation
+
+### Environment Variables
+
+For the environment variables, you will need to configure on your local system (and any deployment machines) the following environment variables:
+
+- DB_PORT (default: 5432)
+- DB_USER (default: postgres)
+- DB_PASSWORD (default: password)
+- DB_NAME (default: postgres)
+
+Changing only the user and password then running `$make env` should be sufficient.
+
+### Postgres Installation
+
+#### MacOS
+
+- `brew install postgresql chromedriver`
+- Start postgres if necessary. `brew services start postgresql`
+
+#### Linux/WSL
+
+- `sudo apt install postgresql`
+- Create a postgres user.
+  - `sudo su - postgres` (to get into postgres shell)
+  - `createuser --interactive --pwprompt` (in postgres shell)
+  - Save `DB_USER` and `DB_PASSWORD` fields in the `.env` file.
+- Start postgres if necessary. `pg_ctlcluster 12 main start`
+  - Note: if you are using WSL2 on windows, the command to start postgres is `sudo service postgresql start`
+
+### Stand Up Server
+
+In order to stand up the server with [Overmind](https://github.com/DarthSim/overmind) in dev, run:
+
+```bash
+make dev
+```
+
+*NOTE:* The Overmind binary is stored in `bin/overmind` and needs to be maintained manually.