[ Branding ] Rebrand repo to align to Seqera standard

[gwright99]

Background

As the title says, we need to style this public-facing repo to be consistent with other Seqera public-facing repos.

Reference project: https://github.com/seqeralabs/template-oss-repo

[gwright99]

@FloWuenne -- we may come knocking to leverage your recent experience re: your own repo rebrand.