Add paket install snippet to site

[mjgpy3]

Pretty easy one, put it next to the NuGet instructions

[MetalDent]

Hi @mjgpy3 in which file will this go?

[mjgpy3]

@MetalDent the doc source index file file would be fine. Then the documentation will need to be built using FAKE after in the commit.

[MetalDent]

@mjgpy3 I forked and checked out the repo, there is already .paket folder. So what do you want to change? Like you just want a demo for paket and FAKE? Or want to add something else?