add an example for axios global config

2021-03-19_axios-01-start/src/components/dashboard/dashboard.vue

@@ -15,7 +15,7 @@ export default {
         }
     },
     created(){
-        axios.get("https://axios-test-44b62-default-rtdb.europe-west1.firebasedatabase.app/users.json")
+        axios.get('/users.json')
             .then(response => {
                 console.log(response)
                 const data = response.data

2021-03-19_axios-01-start/src/main.js

@@ -4,6 +4,8 @@ import App from './App.vue'
 import router from './router'
 import store from './store'
 
+import axios from "axios"
+axios.defaults.baseURL = "https://axios-test-44b62-default-rtdb.europe-west1.firebasedatabase.app"
 new Vue({
   el: '#app',
   router,