Simplify the "Try it" section

[qu1queee]

Idea:

From @sbose78 , can we simplify https://github.com/shipwright-io/build#try-it into a one-liner kubectl cmd?

[zhangtbj]

The current v0.3.0 release doesn't include the release.yaml

It should be included in the later release, such as: https://github.com/shipwright-io/build/releases/tag/untagged-52d78119a4e5d84137cb

Release v0.3.1-rc0
This is a test release to generate the release.yaml via ko. This is not intended to be a bugfix release.

After that, we can refine the Try it section

[adambkaplan]

We now have nightly release YAMLs that will let users install Shipwright directly - we can phrase this as "To install the latest nightly build, run ..."

[sbose78]

Nice!

[zhangtbj]

As we discussed, we planed to use the nightly release yaml directly.

But I took a look at the nightly yaml today from here:
https://github.com/shipwright-io/build/releases/tag/nightly

I found there is a date and random value in the yaml name, like: nightly-2021-03-03-1614768199.yaml

So it is hard to get the latest nightly yaml file name directly for this issue.

So I suggest we have a nightly-latest.yaml file so the the Try It can use it without any change every day.

[qu1queee]

Closing this one in favor of #655 . 655 will cover the requirement in here.