Move Settings tab navigation to the main sidebar menu

Closes #155 (closed) and #154 (closed)

This MR mocks the list of tabs used to render menu in the Settings section. !202 should be merged when the required backend changes are made (pleroma!3348 (closed))

src/api/settings.js

@@ -14,7 +14,7 @@ export async function deleteInstanceDocument(name, authHost, token) {
 export async function fetchDescription(authHost, token) {
   return await request({
     baseURL: baseName(authHost),
-    url: `/api/pleroma/admin/config/descriptions`,
+    url: `/api/v2/pleroma/admin/config/descriptions`,
     method: 'get',
     headers: authHeaders(token)
   })