Add PERIAN Job Platform Agent example

[otarabai]

The PERIAN agent is already merged here.

[neverett]

I left a few suggestions that you can accept as you see fit, but there are two changes you'll need to make to get the docs to build correctly and make tests pass:

• Update the LABEL format in the Dockerfile
• Add an entry to the toctree at the bottom of the integrations/index.md file

[otarabai]

Thanks a lot for the suggestions @neverett. I've applied them all and also updated the example_template.

[neverett]

@otarabai This looks great, and thanks for updating the template! Looks like the DCO check is failing, would you be able to sign off on your commits?

[otarabai]

@neverett My mistake. Just signed them off.

[pingsutw]

LGTM, thanks. @otarabai could you help fix the merge conflict?

[neverett]

@otarabai one other thing -- could you add flytekit documentation for this agent? You will need to add a perian.rst page to the flytekit/docs/source/plugins directory (you can check the other plugin pages to see how to format the page), and update the plugins index page with an entry for the Perian agent. Feel free to tag me on that PR when you open it and let me know if you have any questions. Thanks!

[otarabai]

Thanks @pingsutw! I rebased and fixed the conflicts.
@neverett I'll add the flytekit docs right away :)

[otarabai]

...and fixed the lint error