Update WebInterface.php

Improved some examples and fixed another typo.
Update MinkJS.php

Improved documentation on wait() and waitForJS()
Updated initial Selenium instructions to help newbies (like myself)

Some of the instructions were a little sparse and I had to go through some troubleshooting until I got things working.  Hoping these instructions will help others.
Merge pull request #423 from SimonEast/patch-1

Updated initial Selenium instructions to help newbies (like myself)
Merge pull request #420 from Tro95/patch-3

Update MinkJS.php
Merge pull request #419 from Tro95/patch-2

Update WebInterface.php
Update MinkJS.php

Forgot quotes + added one more example
Merge pull request #424 from Tro95/patch-4

Update MinkJS.php