Improving cache performance page

[cflcrowter]

Summary

Improving suggestions on the cache performance page and changing references for page rules to cache rules.

Documentation checklist

• [x ] The documentation style guide has been adhered to.

[cflcrowter]

@lougayou Would you be able to cast an eye over this one please? Thanks.

[ngayerie]

hey @alekrumkamp , how does it look for you? Anything that should be added here?

[angelampcosta]

@cflcrowter @ngayerie is it ok if I merge? I'll create another PR to update https://developers.cloudflare.com/cache/how-to/cache-rules/examples/cache-everything/