name devices at login "Hydrogen"

so you can somewhat identify them in a device list

src/matrix/SessionContainer.js

@@ -89,7 +89,7 @@ export class SessionContainer {
         let sessionInfo;
         try {
             const hsApi = new HomeServerApi({homeServer, request: this._request, createTimeout: this._clock.createTimeout});
-            const loginData = await hsApi.passwordLogin(username, password).response();
+            const loginData = await hsApi.passwordLogin(username, password, "Hydrogen").response();
             const sessionId = this.createNewSessionId();
             sessionInfo = {
                 id: sessionId,

src/matrix/net/HomeServerApi.js

@@ -141,14 +141,15 @@ export class HomeServerApi {
             {}, {}, options);
     }
 
-    passwordLogin(username, password, options = null) {
+    passwordLogin(username, password, initialDeviceDisplayName, options = null) {
         return this._post("/login", null, {
           "type": "m.login.password",
           "identifier": {
             "type": "m.id.user",
             "user": username
           },
-          "password": password
+          "password": password,
+          "initial_device_display_name": initialDeviceDisplayName
         }, options);
     }