Update index.

README.md

@@ -334,6 +334,7 @@ Note: you can install even more cheat sheets in your local browser using the
  - [Awesome k8s Security](https://github.com/magnologan/awesome-k8s-security)
  - [Bash Handbook](https://github.com/denysdovhan/bash-handbook)
  - [Bayesian Modelling in Python](https://github.com/markdregan/Bayesian-Modelling-in-Python)
+ - [Databases Introduction](https://github.com/anhthii/database-notes)
  - [DevOps Video Tutorials](https://github.com/antonputra/tutorials)
  - [DevSecOps Maturity Model](https://github.com/devsecopsmaturitymodel/DevSecOps-MaturityModel)
  - [DevSecOps SLSA Framework](https://github.com/slsa-framework/slsa)
@@ -355,6 +356,7 @@ Note: you can install even more cheat sheets in your local browser using the
  - [JS Promise Cookbook](https://github.com/mattdesl/promise-cookbook)
  - [Java 8 Tutorial](https://github.com/winterbe/java8-tutorial)
  - [Javascript Functional Programming](https://github.com/MostlyAdequate/mostly-adequate-guide)
+ - [Kafka Architecture](https://github.com/anhthii/kafka-notes)
  - [Learn Regex](https://github.com/ziishaned/learn-regex)
  - [Learn To Cloud](https://github.com/learntocloud/learn-to-cloud)
  - [Learn Vim](https://github.com/iggredible/Learn-Vim)