feat: add font fallbacks to limit cls

[ramboz]

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 #139

Test URLs:

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

[aem-code-sync[bot]]

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[bot]]

Page	Score	PSI Audit	Google
/us/en/skymiles/how-to-earn-miles/overview

[aem-code-sync[bot]]

Page	Score	PSI Audit	Google
/us/en/skymiles/how-to-earn-miles/overview

[aem-code-sync[bot]]

Page	Score	PSI Audit	Google
/us/en/skymiles/how-to-earn-miles/overview