Fix typo

Author: jcs090218

README.md

@@ -8,7 +8,7 @@ Emacs package command-line tool
 
 [![CI](https://github.com/emacs-eask/eask/actions/workflows/test.yml/badge.svg)](https://github.com/emacs-eask/eask/actions/workflows/test.yml)
 
-## 💾 nstallation
+## 💾 Installation
 
 N/A