Add export option to right panel

res/css/views/right_panel/_RoomSummaryCard.scss

@@ -239,3 +239,7 @@ limitations under the License.
 .mx_RoomSummaryCard_icon_settings::before {
     mask-image: url('$(res)/img/element-icons/settings.svg');
 }
+
+.mx_RoomSummaryCard_icon_export::before {
+    mask-image: url('$(res)/img/element-icons/export.svg');
+}

res/img/element-icons/export.svg

@@ -0,0 +1,14 @@
+<svg
+ width="24"
+ height="24"
+ viewBox="0 0 24 24"
+ fill="none"
+ xmlns="http://www.w3.org/2000/svg"
+>
+ <path
+  fill-rule="evenodd"
+  clip-rule="evenodd"
+  d="M12 22C17.5228 22 22 17.5228 22 12C22 6.47715 17.5228 2 12 2C6.47716 2 2 6.47715 2 12C2 17.5228 6.47715 22 12 22ZM12.7071 17.7071C12.6112 17.803 12.5007 17.8753 12.3828 17.9241L11.2929 17.7071L11.2925 17.7067L7.2929 13.7071C6.90237 13.3166 6.90237 12.6834 7.2929 12.2929C7.68342 11.9024 8.31658 11.9024 8.70711 12.2929L11 14.5858L11 7C11 6.44771 11.4477 6 12 6C12.5523 6 13 6.44771 13 7L13 14.5858L15.2929 12.2929C15.6834 11.9024 16.3166 11.9024 16.7071 12.2929C17.0976 12.6834 17.0976 13.3166 16.7071 13.7071L12.7071 17.7071ZM12.3828 17.9241L11.295 17.7092C11.4758 17.8889 11.7249 18 12 18C12.1356 18 12.2649 17.973 12.3828 17.9241Z"
+  fill="#C1C6CD"
+ />
+</svg>

src/components/views/right_panel/RoomSummaryCard.tsx

@@ -279,6 +279,9 @@ const RoomSummaryCard: React.FC<IProps> = ({ room, onClose }) => {
             <Button className="mx_RoomSummaryCard_icon_settings" onClick={onRoomSettingsClick}>
                 {_t("Room settings")}
             </Button>
+            <Button className="mx_RoomSummaryCard_icon_export" onClick = {() => {}}>
+                {_t("Export chat")}
+            </Button>
         </Group>
 
         { SettingsStore.getValue(UIFeature.Widgets) && <AppsSection room={room} /> }

src/i18n/strings/en_EN.json

@@ -1790,6 +1790,7 @@
     "Show files": "Show files",
     "Share room": "Share room",
     "Room settings": "Room settings",
+    "Export chat": "Export chat",
     "Trusted": "Trusted",
     "Not trusted": "Not trusted",
     "%(count)s verified sessions|other": "%(count)s verified sessions",