Point to --filter CLI documentation please

**Related command**

az sp list --filter ...

**Is your feature request related to a problem? Please describe.**

I cannot find the correct syntax of the filter giving me all the principals containing a substring in the name. the --filter part only mentions the eq operator and I can't find the other ones or a reference to where they are specified.

**Describe the solution you'd like**

If the --filter is common to many commands, please add a link to its specification whenever we land to documentation like the one in this page.
I am looking for a command like
`az sp list -o table --filter "displayName contains 'my string'"`

**Describe alternatives you've considered**

I have tried to look for the information with various engines, including the one on the documentation itself, but I can't find pertinent information. The engines point me to something like https://learn.microsoft.com/en-us/graph/filter-query-parameter?tabs=http, but those operators do not work, therefore I assume this --filter is a different implementation.

The only working alternative is to list all principals in a file, then use text editing capabilities to filter.

**Additional context**