docs: Add React Finland 2020 (#2275)

content/community/conferences.md

@@ -82,6 +82,11 @@ May 4-6, 2020. Atlanta, GA, USA.
 
 [Website](https://renderatl.com) - [Twitter](https://twitter.com/renderATL) - [Instagram](https://www.instagram.com/renderatl/) - [Facebook](https://www.facebook.com/renderatl/) 
 
+### React Finland 2020 {#react-finland-2020}
+May 26-29 in Helsinki, Finland
+
+[Website](https://react-finland.fi/) - [Twitter](https://twitter.com/ReactFinland)
+
 ### React Next 2020 {#react-next-2020}
 June 15, 2020. Tel Aviv, Israel.