feat: use jenkins io components header/footer

[shlomomdahan]

This commit fixes #14

I included the Jenkins IO footer as well on the landing page

[lemeurherve]

Thanks for the PR!

You might want to revise bottom margin to avoid the content to be hidden behind the footer:

(As seen on https://deploy-preview-16--stats-jenkins-io.netlify.app/)

[shlomomdahan]

@timja

Yes - that was intentional. I can add it if necessary, I just thought that it did not look good on those pages.

[krisstern]

Footer only seems to be there on the home page not on others

We have had some internal discussion about this before, and decided against having footers except for the landing page.