fix: enhance addSettings method to handle stack variables and live preview settings

Author: harshithad0703

lib/stack/index.js

@@ -631,12 +631,19 @@ export function Stack (http, data) {
      * .then((settings) => console.log(settings))
      *
      */
-    this.addSettings = async (variables = {}) => {
+    this.addSettings = async (stackVariables = {}) => {
       try {
-        const response = await http.post(`${this.urlPath}/settings`, { stack_settings: variables },
-          { headers: {
-            ...cloneDeep(this.stackHeaders)
-          } })
+        const payloadBody = (
+          'stack_variables' in stackVariables ||
+          'live_preview' in stackVariables ||
+          'rte' in stackVariables
+        )
+          ? { stack_settings: stackVariables }
+          : { stack_settings: { stack_variables: stackVariables } }
+
+        const response = await http.post(`${this.urlPath}/settings`, payloadBody, { headers: {
+          ...cloneDeep(this.stackHeaders)
+        } })
         if (response.data) {
           return response.data.stack_settings
         } else {