docs: go get latest (potentially untagged) module in quickstart

[rollulus]

Using a go get without the version installs the latest tagged release. The documentation on the website can be more recent, potentially relying on functionality that's not in the latest tagged release yet.

What does this PR do?

Instruct to go get @main in quickstart.

Why is it important?

Using a go get without the version installs the latest tagged release. The documentation on the website can be more recent, potentially relying on functionality that's not in the latest tagged release yet.

Related issues

#511

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[stevenh]

I understand the intent, but IMO we shouldn't be encouraging folks to use main unless they have a specific need, e.g. testing an unreleased feature.

Instead I would make it clear that the docs here could include unreleased changes, which should be clearly documented and point them towards the pkg.go.dev which provides versioned documentation if they need to validate.

@mdelapenya thoughts?

[mdelapenya]

@stevenh you are right. Given #511 is still around, regarding the docs system and the multiversion system, I'd consider our website as a best effort towards sharing knowledge about main. From the modules standpoint, we always try to add the version functions and methods appeared for a given module, which is what pkg.go.dev did pretty well. So, following on @stevenh's advice, we could add that message linking to pkg.go.dev in the quickstart guide, with the warning regarding the versioning.

I think I can dedicate time to look at #511 again, but I'll be after the ongoing PRs regarding the reaper and the new modules.

[rollulus]

Ok, got it, I think this then ends what I can do as a random visitor. Thanks.

[mdelapenya]

In any case thanks @rollulus for your random visit :) I helped us in talking again about #511

Please come again and provide any feedback you consider, specially about docs. We are doing our best in keeping them up-to-date, but many times is difficult because of the bandwidth.

Cheers!