Add documentation for constructing Stim circuits for standalone use with tqecd

[ShuwenKan]

Currently, there is no documentation explaining how to construct a stim.Circuit when using tqecd as a standalone tool to annotate detectors.

I can work on adding a new section to the documentation that outlines key guidelines for circuit construction, based on the internal behavior of the annotate_detectors_automatically() function.

[nelimee]

I assigned you following your "I can work on adding a new section [...]", please tell me if you don't want to be assigned anymore.