Update README.md (#26)

Make clear Node 8 is required and provide help for common caveats.

README.md

@@ -5,14 +5,16 @@ Dynamo Dictionary development repo
 Live version here: http://dictionary.dynamobim.com
 
 ## Installation
+- Version 8 of Node is required. Later versions of Node are known to cause installation problems.
 - In root directory, type ```npm install``` into the command line.
+- If you find that the command hangs, feel free to use `yarn` instead of `npm`.
 
 ## Run in Development Mode
 - In root directory, type ```npm run start``` into the command line.
 
 ## Deploy to Autodesk
 
-- confirm that `homepage` in `package.json` is set to `http://dictionary.dynamobim.com/`. The developer may change this address depending on the staging environment.
+- Confirm that `homepage` in `package.json` is set to `http://dictionary.dynamobim.com/`. The developer may change this address depending on the staging environment.
 
 - In root directory: ```npm run build```