Device manager - add settings subsection heading component (#9387)

* add settings subsection heading component

* use named export

* newline

src/components/views/settings/shared/SettingsSubsectionHeading.tsx

@@ -0,0 +1,31 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React, { HTMLAttributes } from "react";
+
+import Heading from "../../typography/Heading";
+
+export interface SettingsSubsectionHeadingProps extends HTMLAttributes<HTMLDivElement> {
+    heading: string;
+    children?: React.ReactNode;
+}
+
+export const SettingsSubsectionHeading: React.FC<SettingsSubsectionHeadingProps> = ({ heading, children, ...rest }) => (
+    <div {...rest} className="mx_SettingsSubsectionHeading">
+        <Heading className="mx_SettingsSubsectionHeading_heading" size='h3'>{ heading }</Heading>
+        { children }
+    </div>
+);