manifest.json

{
    "manifest_version": 2,

    "name": "Medium korea font",
    "description": "change medium font-family for korean user",
    "version": "2.1",
    "background" : {
       "scripts": ["background.js"],
       "persistent": false
    },
    "content_scripts": [
        {
            "matches": ["http://medium.com/*", "https://medium.com/*"],
            "css": ["korea_font_family.css", "fonts/nanumgothic.css", "fonts/jejumyeongjo.css", "fonts/notosanskr.css", "fonts/kopubbatang.css"],
            "js": ["content.js"]
        }
    ],
    "browser_action": {
        "default_icon": "icon.png",
        "default_title": "Medium korea font"
    },
    "options_ui": {
        "page": "options.html",
        "chrome_style": true,
        "open_in_tab": true
    },
    "web_accessible_resources":["fonts/*"],
    "permissions": [ "declarativeContent", "fontSettings", "storage", "contextMenus", "activeTab" ],
    "icons": { "16": "icon-16.png",
           "48": "icon-48.png",
          "128": "icon-128.png" }
}