feat: adds a basic README.md and an empty CONTRIBUTING.md

[jacoscaz]

This PR walks the same path of #30 , though stopping a few steps earlier as per the provided feedback.

Regardless of whether this PR is accepted by the group or not, as chair I much prefer things to be explicit. The reference to https://www.w3.org/Consortium/cepc , though not necessary as this repo is implicitly governed by CEPC, is there because it immediately clarifies the matter of whether we have adopted a Code of Conduct or not without relying on a-priori knowledge on the reader's part. Any PR looking to add a README.md file should, in my opinion, make this explicit.

I've left the CONTRIBUTING.md file intentionally empty as it'll be the focus of different PRs.

EDIT: I've managed to get the spelling of CONTRIBUTING wrong in three different ways. New record.

[melvincarvalho]

LGTM

[jonassmedegaard]

Looks good to me.

[jacoscaz]

/chair hat on

Merging this in based on:

• feedback on this specific PR
• feedback on #30, of which this is a subset
• feedback on #49, which builds upon this one
• the fact that this reflects the current state of the CG as-is

We can add more as we go along.