Update index.md

Add embedchain. 
Embedchain is an open source framework for software developers who doesn't know AI but wants to integrate AI
It has a lot of beginner-friendly issues and fixing these issues a developer will end up learning about AI and open source both.

Author: taranjeet

collections/choosing-projects/index.md

@@ -9,6 +9,7 @@ items:
  - cloudquery/cloudquery
  - EddieHubCommunity/LinkFree
  - Ileriayo/markdown-badges
+ - embedchain/embedchain
 
 display_name: How to choose (and contribute to) your first open source project
 created_by: kytrinyx