Add require-extension rule to Readme

Author: yannickcr

README.md

@@ -56,6 +56,7 @@ Finally, enable all of the rules that you would like to use.
     "react/no-unknown-property": 1,
     "react/prop-types": 1,
     "react/react-in-jsx-scope": 1,
+    "react/require-extension": 1,
     "react/self-closing-comp": 1,
     "react/sort-comp": 1,
     "react/wrap-multilines": 1
@@ -79,6 +80,7 @@ Finally, enable all of the rules that you would like to use.
 * [no-unknown-property](docs/rules/no-unknown-property.md): Prevent usage of unknown DOM property
 * [prop-types](docs/rules/prop-types.md): Prevent missing props validation in a React component definition
 * [react-in-jsx-scope](docs/rules/react-in-jsx-scope.md): Prevent missing React when using JSX
+* [require-extension](docs/rules/require-extension.md): Restrict file extensions that may be required
 * [self-closing-comp](docs/rules/self-closing-comp.md): Prevent extra closing tags for components without children
 * [sort-comp](docs/rules/sort-comp.md): Enforce component methods order
 * [wrap-multilines](docs/rules/wrap-multilines.md): Prevent missing parentheses around multilines JSX