flesh out access token README docs

README.md

@@ -27,11 +27,15 @@ First off: if you hit problems during development try:
 
 This will clear cached build data and update to the latest versions of dependencies.
 
-The demo applications use Mapbox vector tiles, which require a Mapbox account and API access token. Obtain an access token on the [Mapbox account page](https://www.mapbox.com/account/apps/) and paste it in the `access_token.hpp` file before building the demo projects.
+### Mapbox API access tokens
+
+The demo applications use Mapbox vector tiles, which **require a Mapbox account and API access token**. Obtain an access token on the [Mapbox account page](https://www.mapbox.com/account/apps/). 
 
 ## OS X
 
-First run:
+Insert your access token into `access_token.hpp`. 
+
+Run:
 
     make setup
 
@@ -54,6 +58,8 @@ First, pull down the submodule(s):
     git submodule init
     git submodule update
 
+Insert your access token into `MBXViewController.h`. 
+
 Then run:
 
     make setup
@@ -66,6 +72,8 @@ Target devices: iPhone 4 and above (4S, 5, 5c, 5s) and iPad 2 and above (3, 4, m
 
 ## Ubuntu
 
+Insert your access token into `access_token.hpp`. 
+
 Ensure you have git and other build essentials:
 
     sudo apt-get update