fix(dashboards): Update overlay to data series (#11803)

Moving from the word "overlay" to "data series" in dashboards.

Author: narsaynorath

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

@@ -36,7 +36,7 @@ Each chart type allows you to solve different problems:
 
 - Area charts are ideal for showing results that are cumulative or where you want to show a breakdown. An example would be “count of errors for each major browser”.
 - Bar charts will group results by day, making them good for daily roll-ups or as “big picture” summaries. An example would be “count of errors per day”.
-- Line charts are a general-purpose visualization. Make sure the Y-Axis units match if you add multiple overlays. Mixing count with duration will not yield useful results.
+- Line charts are a general-purpose visualization. Make sure the Y-Axis units match if you add multiple data series. Mixing count with duration will not yield useful results.
 
 ### Table
 

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

@@ -10,7 +10,7 @@ The widget library contains a collection of prebuilt widgets you can add to your
 
 The library includes the following widgets:
 
-- **Duration Distribution**: A multi-overlay chart visualizing the distribution of transaction duration across various percentiles (p50, p75, and p95)
+- **Duration Distribution**: A multiple data series chart visualizing the distribution of transaction duration across various percentiles (p50, p75, and p95)
 - **High Throughput Transactions**: The top five transactions with the largest number of events, represented in an area chart
 - **LCP by Country**: Table showing the p75 of page load times for each country
 - **Miserable Users**: The total number of unique users who have experienced slow transactions (transaction duration greater than 1200ms)