Update installing-the-cli.md

The previous update made the textual description for Windows unreachable and just referenced a Microsoft article about determining whether you have a 32-bit or 64-bit OS. I would have thought there were easier ways (will have a look when I get the chance). Have added back a link to the textual description.
Merge pull request #78 from Dangthrimble/patch-3

Update installing-the-cli.md