Add links to npm for modules with github url

[jnv]

Just to say that I use node-modules almost daily and I really like it. Sometimes I'd like to check the module's details on NPM instead of going straight to GitHub repo, so I took an initial stab at adding the link:

However this seems a bit redundant, plus the links are maybe too much unobtrusive; perhaps the npm link could be placed next to the package name, since the link already points to GitHub?

[mafintosh]

yea moving the npm link next to the version seems like a better idea :) you wanna update it so i can merge this?

[Kikobeats]

What do you think about:

• pkg name --> link to npm
• in the footer, instead of github, source code and link it

[jnv]

I have switched to npms.io in the meantime, however feel free to use this PR to your heart's content!