Add myself as mbstring maintainer [ci skip]

alexdowad · alexdowad · commit 296f76453c07 · 2022-07-19T20:10:27.000+02:00
diff --git a/EXTENSIONS b/EXTENSIONS
@@ -375,6 +375,7 @@ STATUS:              Working
 EXTENSION:           mbstring
 PRIMARY MAINTAINER:  Rui Hirokawa <hirokawa@php.net> (2001 - 2013)
                      Nikita Popov <nikic@php.net> (2017 - 2020)
+                     Alex Dowad <alexinbeijing@gmail.com> (2021 - 2022)
 MAINTENANCE:         Maintained
 STATUS:              Working
 -------------------------------------------------------------------------------
