Add workflow to publish docker image for self-hosting

[alexklibisz]

Re: #26

Pretty straightforward: checkout the latest tag, build the docker image for the Python flask application, and publish it to Github's container registry, using the git tag as the image tag.

Here's how it looks when it runs: https://github.com/alexklibisz/explain.dalibo.com/actions/runs/8943147452

Here's how it looks when the image is published: https://github.com/alexklibisz/explain.dalibo.com/pkgs/container/pev2/versions

We might want to adjust the name. I chose pev2 for now, but perhaps you want to call it something else.

[alexklibisz]

I see some comments from @pushkar-anand in my email, but not on the PR:

[alexklibisz]

@pushkar-anand if you want to self-host the service, I have an image hosted here: https://github.com/alexklibisz/pev2-docker/pkgs/container/pev2-server

[pushkar-anand]

I see some comments from @pushkar-anand in my email, but not on the PR:

Yes, I got it working so I deleted it. My bad.

My comment was wrong. My fork was missing tags from the upstream so was getting errors when running the action

[alexklibisz]

@pgiraud Could you have a look here? Thanks

[pgiraud]

@alexklibisz first of all I would like to apologize for the long delay.

I decided to take your idea into account in a new PR. It was easier for me to work on this on my side than adding comments to your work.

Please have a look at https://github.com/dalibo/explain.dalibo.com/pull/33. It put you as co-author to the last commit since you initiated the work.

[alexklibisz]

No problem at all. Thanks for picking it up! I'll go ahead and close here since this is covered in #33.