Docs: Need connect null values content (#35070)

* updated content

* Added details on Connect Null Values and changed link for image

* Fixed poor grammar

* Fixed poor grammar

* updated the descriptions and modified some language

* Update docs/sources/panels/visualizations/time-series/graph-time-series-as-lines.md

* Update docs/sources/panels/visualizations/time-series/graph-time-series-as-lines.md

Co-authored-by: Petros Kolyvas <code@petros.io>

docs/sources/panels/visualizations/time-series/graph-time-series-as-lines.md

@@ -146,21 +146,25 @@ Dot spacing set to 0, 30:
 
 ![Line style dots 0, 30 example](/static/img/docs/time-series-panel/line-graph-line-style-dots-0-30-7-4.png)
 
-### Null values
+### Connect null values
 
-Choose how null values (gaps in the data) are displayed on the graph.
+Choose how null values (gaps in the data) are displayed on the graph. Null values can be connected to form a continuous line or, optionally, set a threshold above which gaps in the data should no longer be connected. 
 
-#### Gaps
+![Image name](/static/img/docs/time-series-panel/connect-null-values-8-0.png)
 
-If there is a gap in the series, the line in the graph will be broken and show the gap.
+#### Never
 
-![Null values gaps example](/static/img/docs/time-series-panel/line-graph-null-gaps-7-4.png)
+Time series data points with gaps in the the data are never connected.
 
-#### Connected
+#### Always
 
-If there is a gap in the series, the line will skip the gap and connect to the next non-null value.
+Time series data points with gaps in the the data are always connected.
 
-![Null values connected example](/static/img/docs/time-series-panel/line-graph-null-connected-7-4.png)
+#### Threshold
+
+A threshold can be set above which gaps in the data should no longer be connected. This can be useful when the connected gaps in the data are of a known size and/or within a known range and gaps outside this range should no longer be connected. 
+
+![Image name](/static/img/docs/time-series-panel/connect-null-values-8-0.png)
 
 ### Show points
 

docs/sources/whatsnew/whats-new-in-v8-0.md

@@ -90,6 +90,7 @@ The Time series is out of beta! We are removing the `Beta` tag and graduating th
 - **Time series** is now the default visualization option, replacing the **Graph (old)**.
 - The Time series panel now supports stacking. For more information, refer to [Graph stacked time series]({{< relref "../panels/visualizations/time-series/graph-time-series-stacking.md" >}}).
 - You can now add alerts in the Time series panel, just like the old Graph panel.
+- Updated [connect null values]({{< relref "../panels/visualizations/time-series/graph-time-series-as-lines.md#connect-null-values" >}}) options.
 - We added support for a shared crosshair and a tooltip that’s now smarter when it comes to data display in the tooltip.
 - Various performance improvements.