Revamp the README.md and add link to the awesome list

[simonbrunel]

Integrate the upcoming awesome list and make our README.md welcome page more user friendly:

• display the Chart.js logo (SVG)
• center the logo, tagline and badges
• add a "release" badge linking to the "installation" page
• remove the "maintainabilty" badge (not really useful and actually not in our favor)
• add the "awesome" badge linking to the upcoming awesome repository
• remove the "installation" section which is an incomplete duplicate of this page
• replace the "documentation" section by the documentation TOC
• merge the "contributing" and "building" sections
• add a link to our samples (was previously missing)
• removed the thanks section (will thanks n8agrin on our Twitter account instead)

Inspired from the datalabels plugin README.md, the render can be seen here

[benmccann]

I love this change! The README is so much cleaner now!

Should we also disable code climate from the PRs? It's almost all false positives. Or change the configuration to make it less noisy in which case I think we'd want to leave the badge and change the rules so that we get a better score and alert only on things we actually care about

[kurkle]

I don't think codeclimate should be removed from PRs. Its ok to remove here, but I'd look forward for adding it back some day.

[simonbrunel]

This PR doesn't disable CodeClimate, it removes the "maintainability" badge which is, I think, not useful to display on the home page. First because our score is quite low due to a lot of technical debt issues but also because it doesn't really mean something for our users (we could disable all rules and get the highest score).

I agree with @kurkle, we should not remove the CC integration on PR, neither change the configuration. I don't think it's false positive but instead, cases where we are modifying existing (old) code. So I think it's fine since it encourages us to refactor and/or simplify the existing code.

Also, I don't think the CC integration is "noisy". It only displays a status report that we are free to ignore if we judge it's not important or related to the PR. It also doesn't block from merging the PR. Something that would be great from GH would be an additional "warning" status: "it succeeded but with some warnings".

[simonbrunel]

As discussed with @etimberg, we are going to thanks n8agrin directly from our Twitter account so I removed the whole "Thanks" section.