changes README's hello-world example for v3

[paganotoni]

This PR

• Changes the hello-world example code so it actually works with v3.
• Adds documentation examples for website/content/index.md based on Fix sample code and test command. #667 and this PR.

cc @vishr

[coveralls]

Coverage remained the same at 84.943% when pulling 1eef1cf on apaganobeleno:v3 into 8b8aac8 on labstack:v3.

[coveralls]

Coverage remained the same at 84.845% when pulling 7e5d422 on apaganobeleno:v3 into f720ea1 on labstack:v3.

[paganotoni]

@vishr repurposing this PR, it now adds content to the index based on #667 and also changes hello world example.

Is this ok or i should send this PR in a different way ? WDYT ?

[coveralls]

Coverage remained the same at 84.845% when pulling 07fa1c9 on apaganobeleno:v3 into f720ea1 on labstack:v3.

[vishr]

@apaganobeleno Thanks for your support 👍. Is it ok if I ping you for any documentation related work?

[paganotoni]

@vishr definitely anyway i could help please ping me, also if you have some code-related issues that could serve as a way to get used to the codebase i would be wiling to help :).

[vishr]

@apaganobeleno Thanks, there are open issues labeled help wanted and we definitely need people to fix those.

[vishr]

@apaganobeleno are you available on gitter chat? Question: is v3 readme/index update to latest changes in v2?

[paganotoni]

@vishr i'm not not on gitter, nos sure i understand the question, you mean if v2 README has been updated ? if so, i've not worked on v2 docs yet.

[vishr]

@apaganobeleno Sorry for the confusion. Are changes from this PR (#667) applied into v3 README.md/index.md?

[paganotoni]

@vishr yes, those changes have been applied to v3.

[paganotoni]

@vishr sorry for the confusion, this should have been overwritten by other PR, i was checking in v3 README.md and some changes in the PR are not there.

[vishr]

@apaganobeleno Do you think we can get them back?

[paganotoni]

@vishr sure, i'll work in a PR soon and mention you there, thanks for the heads-up with this.

[vishr]

Check index.md too. Let's get v3 out.