Update Cloudflare cache rules documentation

Problem/Motivation

Discovered today that not all rules are equal.

Following is a raw notes that should be incorporated into a getting started docs :

Logical rule looks like this - if the incoming request have a cookie that starts with SSESS bypass the cache.

Cloudflare UI provides great deal of Cache rule conditions in the UI, but doesn't tell you too much about how they work and the fact that not all rules are working in all accounts.

For example , using "strict wildcard" operator, like (http.cookie strict wildcard r"SSESS*"), wouldn't work in the Pro account, however UI or docs https://developers.cloudflare.com/cache/how-to/cache-rules/settings/#ope... wouldn't tell you that.

Rules not working on Pro:

• (starts_with(http.cookie, "SSESS"))
• (any(starts_with(http.request.headers["cookie"][*], "SSESS")))
• (http.cookie strict wildcard r"SSESS*")

Working rule: (any(http.request.headers["cookie"][*] contains "SSESS"))

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes