readme: include npm install instructions (#65)
readme: include npm install instructions (#65)

Include instructions on installation with npm.
Also update the output of `help v8`.
hhellyer/llnode,hhellyer/llnode,hhellyer/llnode,rnchamberlain/llnode,hhellyer/llnode,rnchamberlain/llnode,rnchamberlain/llnode,rnchamberlain/llnode