Migration to typescript: first step

Add vue cli typescript support
Rename .js to .ts
Use class and annotations in App and NavBar
Add tslint

js/src/graphql/auth.ts

@@ -0,0 +1,16 @@
+import gql from 'graphql-tag';
+
+export const LOGIN = gql`
+mutation Login($email: String!, $password: String!) {
+  login(email: $email, password: $password) {
+    token,
+    user {
+      id,
+    },
+    actor {
+      avatarUrl,
+      preferredUsername,
+    }
+  },
+}
+`;