some enhacements for the footer in the site

[enekofb]

Just was looking into the site ( which are amazing 🎩 )

And browsing around i stood at a couple of suggestions for the footer

• To add the intro link in the docs for someone willing to get the overview https://weaveworks-liquidmetal.github.io/site/docs/intro/
• to modify the link for contributing https://github.com/weaveworks-liquidmetal/contributing as seems it is not found
• might be also adding a link to the community docs https://weaveworks-liquidmetal.github.io/site/docs/community/

[Callisto13]

lol why do i never get notified for things? i swear i fixed my settings 😅

thanks for these notes 🙏