update README.md

Author: iPolyomino

README.md

@@ -1,4 +1,48 @@
-# Kasgai
+<h1 align="center">Kasgai</h1>
+<p align="center">
+    <img width="200" alt="Kasgai Logo" src="kasgai.jpg">
+</p>
+
+## About
+
+Kasgai is the educational application for biginner of programming.
+
+## Getting Started
+
+### Project Download
+
+```zsh
+git clone https://github.com/Kasgai/kasgai.git
+cd kasgai
+git submodule update --init --recursive
+```
+
+### Firebase CLI Install
+
+[Firebase CLI reference](https://firebase.google.com/docs/cli/)
+
+```zsh
+curl -sL https://firebase.tools | bash
+```
+
+### Start Kasgai
+
+```
+cd hosting
+firebase serve
+```
+
+Now you can develop Kasgai!
+
+## Application Composition
+
+Kasgai is composed of the following four applications.
+
+- [yattoko](https://github.com/Kasgai/yattoko)
+- [kegaki](https://github.com/Kasgai/kegaki)
+- [kanna](https://github.com/Kasgai/kanna)
+- [shikkui](https://github.com/Kasgai/shikkui)
 
 ## Index
+
 - [Kasgai Survey](survey.md) The survey system with CSV import.