Merge pull request #33 from Meg528/patch-25

Update lecture-material.mdx

Author: dfreniche

docs/lecture-material.mdx

@@ -6,16 +6,16 @@ sidebar_position: 90
 
 |||
 |-|:-|
-|Practical MongoDB Aggregations Book Online|https://www.practical-mongodb-aggregations.com/|
-|Practical MongoDB Aggregations Book Printed Version|[Packt Publishing](https://www.packtpub.com/product/practical-mongodb-aggregations/9781835080641)|
+|Practical MongoDB Aggregations book online|https://www.practical-mongodb-aggregations.com/|
+|Practical MongoDB Aggregations book printed version|[Packt Publishing](https://www.packtpub.com/product/practical-mongodb-aggregations/9781835080641)|
 |MongoDB University course|https://learn.mongodb.com/courses/mongodb-aggregation|
 |MongoDB Aggregation Pipeline docs|[https://www.mongodb.com/docs/manual/core/aggregation-pipeline/](https://www.mongodb.com/docs/manual/core/aggregation-pipeline/)|
 
 
-## Aggregation Pipeline Cheatsheet
+## Aggregation pipeline cheatsheet
 
 import SamplePDF from '@site/static/pdf/Aggregation Pipelines CheatSheet.pdf';
 
 <object data={SamplePDF} type="application/pdf" width="100%" height="500px">
 <p>Unable to display PDF file. <a href="/pdf/Aggregation Pipelines CheatSheet.pdf">Download</a> instead.</p>
-</object>
+</object>