chore: updating excel docs with some more information (#414)

nbs/docs/reference/03_excel_addin.ipynb

@@ -13,7 +13,7 @@
     "## Usage\n",
     "> 📘 Access token required\n",
     "> \n",
-    "> The TimeGPT Excel Add-in requires an access token. Get your token on the [Nixtla Dashboard](http://dashboard.nixtla.io).\n",
+    "> The TimeGPT Excel Add-in requires an access token. Get your API Key on the [Nixtla Dashboard](http://dashboard.nixtla.io).\n",
     "\n",
     "## Support\n",
     "\n",
@@ -23,9 +23,17 @@
     "\n",
     "### Settings\n",
     "\n",
-    "If it is your first time using the add-in, a welcome screen will guide you to a settings screen to configure your access token.\n",
+    "If this is your first time using Excel add-ins, find information on how to add Excel add-ins with your version of Excel. In the Office Add-ins Store, you'll search for \"TimeGPT\". \n",
     "\n",
-    "To access the setting later, click the gear icon in the top left.\n",
+    "Once you have installed the TimeGPT add-in, the add-in comes up in a sidebar task pane. \n",
+    "* Read through the Welcome screen.\n",
+    "* Click on the **'Get Started'** button.\n",
+    "* The API URL is already set to: https://api.nixtla.io.\n",
+    "* Copy your API key from [Nixtla Dashboard](http://dashboard.nixtla.io). Paste it into the box that say **API Key, Bearer**.\n",
+    "* Click the gray arrow next to that box on the right. \n",
+    "* You'll get to a screen with options for 'Forecast' and 'Anomaly Detection'.\n",
+    "\n",
+    "To access the settings later, click the gear icon in the top left.\n",
     "\n",
     "### Data Requirements\n",
     "\n",
@@ -57,15 +65,20 @@
     "\n",
     "With the add-in open, configure the forecasting settings by selecting the column for each input.\n",
     "\n",
-    "* **Timestamps** - The column of the timeseries timestamps\n",
-    "\n",
-    "* **Values** - The column of the timeseries values for each point in time\n",
-    "\n",
     "* **Frequency** - The frequency of the data (hourly / daily / weekly / monthly)\n",
     "\n",
     "* **Horizon** - The forecasting horizon. This represents the number of time steps into the future that the forecast should predict.\n",
     "\n",
-    "When you're ready, click Run Forecast to generate the predicted values. The add-in will generate a new worksheet with the prediced values and a chart depicting the forecast.\n",
+    "* **Dates Range** - The column and range of the timeseries timestamps. Must not include header data, and should be formatted as a range, e.g. A2:A145. \n",
+    "\n",
+    "* **Values Range** - The column and range of the timeseries values for each point in time. Must not include header data, and should be formatted as a range, e.g. B2:B145. \n",
+    "\n",
+    "\n",
+    "\n",
+    "\n",
+    "\n",
+    "When you're ready, click **Make Prediction** to generate the predicted values. The add-in will generate a plot and append the forecasted data to the end of the column of your existing data and highlight them in green. So, scroll to the end of your data to see the predicted values. \n",
+    "\n",
     "\n",
     "\n",
     "#### Anomaly Detection\n",