Update 1-what-is-aggregation.mdx

Author: Meg528

docs/20-what-is-aggregation/1-what-is-aggregation.mdx

@@ -2,7 +2,7 @@
 description: Learn what an aggregation pipeline is. 
 ---
 
-# 📘 What is an Aggregation Pipeline?
+# 📘 What is an aggregation pipeline?
 
 ![](/img/20-what-is-aggregation/aggregation-pipeline.png)