feat: add image generation plugin

[vtsaplin]

Please always provide the GitHub issue(s) your PR is for, as well as test URLs where your change can be observed (before and after):

Fix #

Test URLs:

• Before: https://main--delta--vtsaplin.hlx.page/us/en/skymiles/how-to-earn-miles/overview
• After: https://genai--delta--vtsaplin.hlx.page/us/en/skymiles/how-to-earn-miles/overview

[aem-code-sync]

Hello, I'm Franklin Bot and I will run some test suites that validate the page speed.
In case there are problems, just click the checkbox below to rerun the respective action.

• Re-run PSI Checks

[aem-code-sync]

Page	Scores	Audits	Google
/us/en/skymiles/how-to-earn-miles/overview		Lighthouse returned error: ERRORED_DOCUMENT_REQUEST. Lighthouse was unable to reliably load the page you requested. Make sure you are testing the correct URL and that the server is properly responding to all requests. (Status code: 404)