Add learning resource for excel (#6163)

w3schools tutorial.

src/data/roadmaps/data-analyst/content/analaysis--reporting-with-excel@sgXIjVTbwdwdYoaxN3XBM.md

@@ -1,3 +1,5 @@
 # Excel
 
-Excel is a powerful tool utilized by data analysts worldwide to store, manipulate, and analyze data. It offers a vast array of features such as pivot tables, graphs and a powerful suite of formulas and functions to help sift through large sets of data. A data analyst uses Excel to perform a wide range of tasks, from simple data entry and cleaning, to more complex statistical analysis and predictive modeling. Proficiency in Excel is often a key requirement for a data analyst, as its versatility and ubiquity make it an indispensable tool in the field of data analysis.
+Excel is a powerful tool utilized by data analysts worldwide to store, manipulate, and analyze data. It offers a vast array of features such as pivot tables, graphs and a powerful suite of formulas and functions to help sift through large sets of data. A data analyst uses Excel to perform a wide range of tasks, from simple data entry and cleaning, to more complex statistical analysis and predictive modeling. Proficiency in Excel is often a key requirement for a data analyst, as its versatility and ubiquity make it an indispensable tool in the field of data analysis.
+
+- [@article@W3Schools - Excel](https://www.w3schools.com/excel/index.php)