Fix connection to back end (#168)

* Add theme toggle and update/fix styling

* Fix broken api calls

Author: gwenf

curriculum-front/.env.local

@@ -1 +1 @@
-VUE_APP_API_URL=http://localhost:5050
+VITE_API_URL=http://localhost:5050

curriculum-front/.env.production

@@ -1 +1 @@
-VUE_APP_API_URL=https://studytracker.tech
+VITE_API_URL=https://studytracker.tech

curriculum-front/src/utils/axiosConfig.js

@@ -1,7 +1,7 @@
 import axios from 'axios'
 // import router from '../router'
 
-axios.defaults.baseURL = `${import.meta.env.VUE_APP_API_URL}/api/v1`
+axios.defaults.baseURL = `${import.meta.env.VITE_API_URL}/api/v1`
 const token = localStorage.getItem('token')
 axios.defaults.headers.common['Authorization'] = token ? `Bearer ${token}` : ''