[v10.4.x] Docs: add legends shared content (#88195)

* Docs: add legends shared content (#86814)

* Updated shared file name and added missing options

* Added legend options 1 shared file to relevant visualizations

* Updated shared file name and corrected options

* Added legend options 2 shared file to relevant visualizations

* Updated legend content for heatmap and pie chart

* Added where shared legend files are used in each file

* Moved intro text out of viz pages into legend options shared files

* Added reasoning to front matter of shared files

* Added reasoning to front matter of shared files

* Fixed version interpolation and added cloud links

* Updated links in shared files

(cherry picked from commit dad3069594)

* Ran prettier

docs/sources/panels-visualizations/visualizations/pie-chart/index.md

@@ -94,25 +94,29 @@ The following example shows a pie chart with **Name** and **Percent** labels dis
 
 Use these settings to define how the legend appears in your visualization. For more information about the legend, refer to [Configure a legend]({{< relref "../../configure-legend" >}}).
 
-### Legend visibility
+### Visibility
 
-Use the **Visibility** switch to show or hide the legend.
+Toggle the switch to turn the legend on or off.
 
-### Legend mode
+### Mode
 
-Set the display mode of the legend:
+Use these settings to define how the legend appears in your visualization.
 
 - **List -** Displays the legend as a list. This is a default display mode of the legend.
 - **Table -** Displays the legend as a table.
 
-### Legend placement
+### Placement
 
 Choose where to display the legend.
 
 - **Bottom -** Below the graph.
 - **Right -** To the right of the graph.
 
-### Legend values
+#### Width
+
+Control how wide the legend is when placed on the right side of the visualization. This option is only displayed if you set the legend placement to **Right**.
+
+### Values
 
 Select values to display in the legend. You can select more than one.