[contents] update user count to 1,000,000 users (#668)

Author: yehiarasheed

README.md

@@ -21,7 +21,7 @@
 
 ## What is this?
 
-Not everyone has the time to do a few hundred LeetCode questions. Here are _free and curated_ technical interview preparation materials for busy engineers, brought to you by me, the author of [Blind 75](https://www.teamblind.com/post/New-Year-Gift---Curated-List-of-Top-75-LeetCode-Questions-to-Save-Your-Time-OaM1orEU). Over 500,000 people have benefitted from this handbook!
+Not everyone has the time to do a few hundred LeetCode questions. Here are _free and curated_ technical interview preparation materials for busy engineers, brought to you by me, the author of [Blind 75](https://www.teamblind.com/post/New-Year-Gift---Curated-List-of-Top-75-LeetCode-Questions-to-Save-Your-Time-OaM1orEU). Over 1,000,000 people have benefitted from this handbook!
 
 Besides the usual algorithm questions, other **awesome** stuff includes: