add prerequisite for postgres and add some titles (#59)

README.md

@@ -4,6 +4,19 @@ Access the live site from [here](https://www.globaldiversitycfpday.com/).
 
 This site is built on Ruby on Rails, using Ruby 2.2.6 and Rails 5.1.1.
 
+## Running the Application
+
+### Prerequisites
+
+This application requires a Postgres database to be available at `localhost` and native postgres drivers to be installed locally. If you see the following error during installation, make sure you have postgres installed.
+
+```bash
+Installing pg 0.18.4 with native extensions
+Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
+```
+
+### Installation
+
 To get this site running locally:
 
 `git clone git@github.com:JiggyPete/global-diversity-cfp-day-site.git`
@@ -12,4 +25,6 @@ Run `bundle install` to get all those lovely Gems on your machine.
 
 Run `rake db:create db:migrate`
 
+### Running
+
 Run `bundle exec rails server` and access `http://localhost:3000` on your browser of choice.