feat(Dashboards): Added new markdown widget docs (#17163)

Markdown widgets can now be created, and we're documenting that. 

---------
Co-authored-by: Shannon Anahata <shannonanahata@gmail.com>

Author: sfanahata

docs/product/dashboards/custom-dashboards/index.mdx

@@ -44,7 +44,7 @@ To restrict who can edit or delete your dashboard, go to the "Edit Access" selec
 
 ## Widget Builder
 
-When adding a widget or editing an existing one, you will be presented with a side panel where you can see the dashboard widget builder. The widget builder has several configuration options that you can use to shape data and add information to your dashboard. Learn more in the [Widget Builder documentation](/product/dashboards/widget-builder/).
+When adding a widget or editing an existing one, you will be presented with a side panel where you can see the dashboard widget builder. The widget builder has several configuration options that you can use to shape data and add information to your dashboard. Visualization types include [area / bar / line chart](/product/dashboards/widget-builder/#area-chart--bar-time-series--line-chart), [table](/product/dashboards/widget-builder/#table), [big number](/product/dashboards/widget-builder/#big-number), and [markdown](/product/dashboards/widget-builder/#markdown). Learn more about the [Widget Builder](/product/dashboards/widget-builder/).
 
 ## Widget Library
 

docs/product/dashboards/widget-builder/img/widget-builder-markdown-visualization.png

@@ -73,6 +73,7 @@ In this step, you can choose from the following visualization types:
 - [Bar (Categorical)](#bar-categorical)
 - [Table](#table)
 - [Big Number](#big-number)
+- [Markdown](#markdown)
 
 ### Area Chart / Bar (Time Series) / Line Chart
 
@@ -100,6 +101,12 @@ Table charts display the results of a [Discover Query](/product/explore/discover
 
 A big number visualization displays the current value of a single function or [equation](/product/explore/discover-queries/query-builder/query-equations/). This visualization is well suited for high-level aggregates. An example scenario would be “p95 of all transactions”.
 
+### Markdown
+
+Markdown visualizations allow you to display plain text or rich markdown content on your dashboard. This is ideal for providing incident playbooks, or other dashboard-specific instructions. When creating a widget, select a custom widget, and *Text (Markdown)* as the visualization type.
+
+![Markdown widget. =700x](./img/widget-builder-markdown-visualization.png)
+
 ## Columns
 
 The option to set columns is only available for [table visualizations](/product/dashboards/widget-builder/#table).

docs/product/dashboards/widget-builder/index.mdx

@@ -7,7 +7,9 @@ description: >-
 og_image: /og-images/product-dashboards-widget-library.png
 ---
 
-The widget library contains a collection of prebuilt widgets you can add to your [custom dashboards](/product/dashboards/custom-dashboards/). You can access the widget library by clicking the "Add Widget" button and selecting "From Widget Library" on the dashboard.
+The widget library contains a collection of prebuilt widgets you can add to your [custom dashboards](/product/dashboards/custom-dashboards/). You can access the widget library by clicking the "Add Widget" button and selecting "From Widget Library" on the dashboard. 
+
+You can also create your own custom widgets using the [Widget Builder](/product/dashboards/widget-builder/). This includes all the visualization types you see in the library, plus the ability to add markdown content to your widgets.
 
 The library includes the following widgets: