Update README with licensing details

Added licensing information for website content and code.

Author: nghtctrl

README.md

@@ -1,3 +1,5 @@
 # [jihokim.dev](https://jihokim.dev)
 
-Welcome to the GitHub repository for my personal website. The site is built with [Astro](https://astro.build/). The favicon <img src="https://github.com/nghtctrl/nghtctrl.github.io/blob/fa3358266ed298c460aa09fc9c339e0d546dbae4/public/wizard.gif" alt="Wizard" width="18"/> comes from [Anthony's Icon Library](https://antofthy.gitlab.io/aicons/).
+Welcome to the GitHub repository for my personal website. The site is built with [Astro](https://astro.build/). The favicon <img src="https://github.com/nghtctrl/nghtctrl.github.io/blob/fa3358266ed298c460aa09fc9c339e0d546dbae4/public/wizard.gif" alt="Wizard" width="18"/> is from [Anthony's Icon Library](https://antofthy.gitlab.io/aicons/).
+
+Unless otherwise noted, all content on the website is licensed under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/). Papers are copyrighted by their respective publishers (e.g., ACM) or repositories with open-access (e.g., arXiv). The code in this repository is licensed under the [MIT License](https://github.com/nghtctrl/nghtctrl.github.io/blob/main/LICENSE).