docs: Fix a few typos (#1197)

There are small typos in:
- README.md

Fixes:
- Should read `unserializable` rather than `unserializeable`.
- Should read `reusable` rather than `reuseable`.
- Should read `related` rather than `releated`.

README.md

 * [Nette](https://nette.org) - A web framework comprised of mature components.
 * [Phalcon](https://phalcon.io/en-us) - A framework implemented as a C extension.
 * [Spiral](https://spiral.dev/) - A high performance PHP/Go framework.
-* [Symfony](https://symfony.com/) - A set of reuseable components and a web framework.
+* [Symfony](https://symfony.com/) - A set of reusable components and a web framework.
 * [Yii2](https://github.com/yiisoft/yii2/) - A fast, secure, and efficient web framework.
 
 ### Framework Extras
 * [HTML Purifier](https://github.com/ezyang/htmlpurifier) - A standards compliant HTML filter.
 * [IniScan](https://github.com/psecio/iniscan) - A tool that scans PHP INI files for security.
 * [Optimus](https://github.com/jenssegers/optimus) - Id obfuscation based on Knuth's multiplicative hashing method.
-* [PHPGGC](https://github.com/ambionics/phpggc) - A library of PHP unserializeable payloads along with a tool to generate them.
+* [PHPGGC](https://github.com/ambionics/phpggc) - A library of PHP unserializable payloads along with a tool to generate them.
 * [PHP Encryption](https://github.com/defuse/php-encryption) - Secure PHP Encryption Library.
 * [PHP SSH](https://github.com/Herzult/php-ssh) - An experimental object orientated SSH wrapper library.
 * [PHPSecLib](http://phpseclib.sourceforge.net/) - A pure PHP secure communications library.
 * [PHP Weekly](https://www.phpweekly.com/) - A weekly newsletter about PHP.
 
 ### PHP Reading
-*PHP-releated reading materials.*
+*PHP-related reading materials.*
 
 * [php[architect]](https://www.phparch.com/magazine/) - A monthly magazine dedicated to PHP.