* feat: add max calculator to limiter middleware
* docs: update docs including the new parameter
* refactor: add new line before go code in docs
* fix: use crypto/rand instead of math/rand on tests
* test: add new test with zero set as limit
* fix: repeated tests failing when generating random limits
* fix: wrong type of MaxCalculator in docs
* feat: include max calculator in limiter_sliding
* refactor: rename MaxCalculator to MaxFunc
* docs: update docs with MaxFunc parameter
* tests: rename tests and add test for limiter sliding