Add rigdern to the issue task force
Add rigdern to the issue task force

Summary:
I've helped contribute around [70 pull requests](https://github.com/facebook/react-native/pulls/rigdern) to React Native and would like to help triage issues.

Adam Comella
Microsoft Corp.
Closes https://github.com/facebook/react-native/pull/16059

Differential Revision: D5884339

Pulled By: hramos

fbshipit-source-id: ba7468fd8e2a5e8f3f054bcafa652a7988f10a78

janicduplessis/react-native,hammerandchisel/react-native,ptmt/react-native-macos,hoangpham95/react-native,exponentjs/react-native,Bhullnatik/react-native,rickbeerendonk/react-native,dikaiosune/react-native,ptmt/react-native-macos,arthuralee/react-native,jevakallio/react-native,Bhullnatik/react-native,hoangpham95/react-native,cdlewis/react-native,rickbeerendonk/react-native,facebook/react-native,rickbeerendonk/react-native,facebook/react-native,facebook/react-native,hammerandchisel/react-native,pandiaraj44/react-native,hoastoolshop/react-native,cdlewis/react-native,arthuralee/react-native,rickbeerendonk/react-native,janicduplessis/react-native,rickbeerendonk/react-native,myntra/react-native,Bhullnatik/react-native,ptmt/react-native-macos,javache/react-native,jevakallio/react-native,hoangpham95/react-native,arthuralee/react-native,frantic/react-native,kesha-antonov/react-native,facebook/react-native,janicduplessis/react-native,cdlewis/react-native,exponentjs/react-native,frantic/react-native,janicduplessis/react-native,pandiaraj44/react-native,arthuralee/react-native,myntra/react-native,kesha-antonov/react-native,hoangpham95/react-native,janicduplessis/react-native,ptmt/react-native-macos,rickbeerendonk/react-native,hoastoolshop/react-native,ptmt/react-native-macos,kesha-antonov/react-native,myntra/react-native,javache/react-native,janicduplessis/react-native,myntra/react-native,hoangpham95/react-native,Bhullnatik/react-native,hammerandchisel/react-native,rickbeerendonk/react-native,hoangpham95/react-native,Bhullnatik/react-native,javache/react-native,javache/react-native,hammerandchisel/react-native,ptmt/react-native-macos,cdlewis/react-native,hoastoolshop/react-native,arthuralee/react-native,facebook/react-native,ptmt/react-native-macos,myntra/react-native,rickbeerendonk/react-native,hoastoolshop/react-native,jevakallio/react-native,cdlewis/react-native,frantic/react-native,hammerandchisel/react-native,exponent/react-native,kesha-antonov/react-native,pandiaraj44/react-native,javache/react-native,myntra/react-native,rickbeerendonk/react-native,jevakallio/react-native,Bhullnatik/react-native,facebook/react-native,pandiaraj44/react-native,exponentjs/react-native,hoastoolshop/react-native,jevakallio/react-native,pandiaraj44/react-native,cdlewis/react-native,javache/react-native,exponent/react-native,cdlewis/react-native,hoastoolshop/react-native,pandiaraj44/react-native,hammerandchisel/react-native,pandiaraj44/react-native,exponent/react-native,kesha-antonov/react-native,janicduplessis/react-native,Bhullnatik/react-native,exponent/react-native,dikaiosune/react-native,jevakallio/react-native,ptmt/react-native-macos,dikaiosune/react-native,kesha-antonov/react-native,dikaiosune/react-native,facebook/react-native,javache/react-native,kesha-antonov/react-native,pandiaraj44/react-native,frantic/react-native,jevakallio/react-native,kesha-antonov/react-native,exponentjs/react-native,facebook/react-native,cdlewis/react-native,exponentjs/react-native,dikaiosune/react-native,javache/react-native,exponentjs/react-native,facebook/react-native,dikaiosune/react-native,myntra/react-native,javache/react-native,exponent/react-native,hoastoolshop/react-native,jevakallio/react-native,dikaiosune/react-native,exponent/react-native,exponentjs/react-native,myntra/react-native,hammerandchisel/react-native,hoangpham95/react-native,exponentjs/react-native,exponent/react-native,jevakallio/react-native,hoangpham95/react-native,dikaiosune/react-native,hammerandchisel/react-native,hoastoolshop/react-native,janicduplessis/react-native,frantic/react-native,cdlewis/react-native,myntra/react-native,exponent/react-native,kesha-antonov/react-native,Bhullnatik/react-native