Add related project modern-errors-plugins

Author: ehmicky

README.md

@@ -296,8 +296,8 @@ logProcessErrors({ colors: false })
 
 - [`modern-errors`](https://github.com/ehmicky/modern-errors): Handle errors
   like it's 2022 🔮
-- [`error-custom-classes`](https://github.com/ehmicky/error-custom-classes):
-  Create multiple error classes
+- [`modern-errors-plugins`](https://github.com/ehmicky/modern-errors-plugins):
+  Plugins for `modern-errors`
 - [`error-custom-class`](https://github.com/ehmicky/error-custom-class): Create
   one error class
 - [`error-class-utils`](https://github.com/ehmicky/error-class-utils): Utilities