Documentation: clearer guidance on creating OAuth 2 client ID
Documentation: clearer guidance on creating OAuth 2 client ID

Provides a more accurate walk through of the screens and menus of the Google
Developers Console encountered whilst creating a client ID.

Fixes #125

Signed-off-by: Chris Swan <da39a3ee5e6b4b0d3255bfef95601890afd80709@cpswan>

zlabjp/dex,andrewstuart/dex,sercand/dex,sercand/dex,sercand/dex,zlabjp/dex,bcwaldon/dex,Tecsisa/dex,jhuntoo/dex,jhuntoo/dex,bcwaldon/dex,Tecsisa/dex,andrewstuart/dex,zlabjp/dex,Tecsisa/dex,andrewstuart/dex,jhuntoo/dex,bcwaldon/dex