Add strings.

en.json

@@ -11,10 +11,12 @@
         "username": "Username",
         "email": "Email",
         "password": "Password",
+        "invite": "Invite Code",
         "enter": {
             "username": "Enter a username.",
             "email": "Enter your email.",
-            "password": "Enter your password."
+            "password": "Enter your password.",
+            "invite": "Enter your invite code."
         },
         "forgot": "Forgot your password?",
         "reset": "Reset password",
@@ -181,12 +183,17 @@
         "internal_error": "Internal error.",
         "unknown_error": "See console.",
         "operation_failed": "Operation failed.",
+        "render_fail": "Template rendering failed.",
         "missing_headers": "Missing headers.",
         "invalid_session": "Invalid session.",
         "unverified_account": "Unverified account.",
         "unknown_user": "Unknown user.",
         "email_in_use": "Email in use.",
-        "wrong_password": "Wrong password.",
+        "email_failed": "Email failed to send.",
+        "invalid_credentials": "Email or password is wrong.",
+        "invalid_token": "Invalid token",
+        "missing_invite": "Missing invite code in request.",
+        "invalid_invite": "Invalid code",
         "already_onboarded": "Already finished onboarding.",
         "username_taken": "Username is taken.",
         "already_friends": "Already friends with this user.",