Add Sohrab Chegini to contributors list

See [#71].

[#71]: #71

Author: sohrb

content/faq/contributors.md

@@ -121,6 +121,10 @@ Helmet has help from a lot of contributors. Thanks to everyone on this list!
     - [helmet#286](https://github.com/helmetjs/helmet/pull/286)
   - [Shane Tomlinson](https://shanetomlinson.com)
     - [csp#43](https://github.com/helmetjs/csp/pull/43)
+  - [Sohrab Chegini](https://github.com/sohrb)
+    - [helmet#465](https://github.com/helmetjs/helmet/pull/465)
+    - [helmet#464](https://github.com/helmetjs/helmet/pull/464)
+    - [helmet#459](https://github.com/helmetjs/helmet/pull/459)
   - [Tara Vancil](https://taravancil.com)
     - [helmet#142](https://github.com/helmetjs/helmet/pull/142)
   - [Teppei Sato](https://github.com/teppeis)