docs: avoid suggesting to push all tags

[stefano-garzarella]

git push --tags ... pushes all refs under refs/tags. So even local development tags could be pushed by mistake. Let's avoid this by suggesting to push only the newly created tag.

[stefano-garzarella]

I personally always create the tags using the GitHub UI, maybe we can add that to the instructions, too?

Yep, that could be good to add!