Resolve routing props type error

app/javascript/packs/frontend/components/pages/pokemon/index.tsx

@@ -1,4 +1,5 @@
 import React from 'react';
+import {RouteComponentProps} from 'react-router'; //eslint-disable-line no-unused-vars
 import {Link} from 'react-router-dom';
 
 import {Pokemon} from '../../../api';
@@ -12,7 +13,7 @@ interface State {
   pokemon: Pokemon[];
 }
 
-class PokemonIndex extends React.Component<void, State> {
+class PokemonIndex extends React.Component<RouteComponentProps<void>, State> {
   public state = {
     pokemon: [],
   };