* random: Remove redundant “Returns” prefix from return value explanation
* random: Document Engine::generate()'s return value
* random: Document Xoshiro256StarStar::generate()'s return value
* random: Document PcgOneseq128XslRr64::generate()'s return value
* random: Document Mt19937::generate()'s return value
* random: Document Secure::generate()'s return value
* random: Document the Randomizer::$engine property
* random: Clarify the int seeding for PcgOneseq128XslRr64
This change is relevant for negative seed values.
* random: Document Mt19937::__construct()'s parameter value
* random: Add description for CryptoSafeEngine
* random: Add description for RandomError
* random: Add description for RandomException
* random: Improve phrasing for MT_RAND_PHP for Mt19937
Co-authored-by: George Peter Banyard <girgias@php.net>
* random: Explain the `$mode` parameter for Mt19937 construction with a list
Co-authored-by: George Peter Banyard <girgias@php.net>