docs: Improve title

README.md

@@ -1,6 +1,9 @@
-## GitHub Actions for GitHub Pages
+<h2 align="center">
+GitHub Actions for GitHub Pages
+</h2>
 
-<img width="400" alt="GitHub Actions for deploying to GitHub Pages with Static Site Generators" src="./images/ogp.svg">
+<div align="center">
+  <img width="400" alt="GitHub Actions for deploying to GitHub Pages with Static Site Generators" src="./images/ogp.svg">
 
 [![license](https://img.shields.io/github/license/peaceiris/actions-gh-pages.svg)](https://github.com/peaceiris/actions-gh-pages/blob/main/LICENSE)
 [![release](https://img.shields.io/github/release/peaceiris/actions-gh-pages.svg)](https://github.com/peaceiris/actions-gh-pages/releases/latest)
@@ -9,6 +12,8 @@
 ![Code Scanning](https://github.com/peaceiris/actions-gh-pages/workflows/Code%20Scanning/badge.svg?event=push)
 [![CodeFactor](https://www.codefactor.io/repository/github/peaceiris/actions-gh-pages/badge)](https://www.codefactor.io/repository/github/peaceiris/actions-gh-pages)
 
+</div>
+
 This is a **GitHub Action** to deploy your static files to **GitHub Pages**.
 This deploy action can be combined simply and freely with [Static Site Generators]. (Hugo, MkDocs, Gatsby, mdBook, Next, Nuxt, and so on.)