Fix incorrect description of glob matching

[zhimsel]

Description of the change

The previous description of how globs are matched is incorrect.

Since the underlying "evaluation engine" is simply an OPA policy (which is described here), the Golang doublestar library has nothing to do with the evaluation. OPA uses its own built-in glob evaluation, which does not follow the same rules as doublestar. See this Rego Playground for examples of where they don't match your docs (the ones reported as "broken").

Additionally, if any custom push policies are attached, the default policy gets thrown out; it's purely up to those policies to interpret the project globs however they see fit (if at all).

This PR modifies the glob section to point to the correct documentation for pattern matching, and updates the examples for quality and accuracy.

Checklist

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  • Both nav.yaml and nav.self-hosted.yaml have been updated.

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