Show notification 30 minutes before contest

[conlacda]

• Add an alarm button next to the contest's name
• Set a timer to show notification
• Add settings (how many minutes before the contest)

[conlacda]

Sample code:

chrome.runtime.onInstalled.addListener(() => {
    chrome.notifications.create({
        type: 'basic',
        iconUrl: '/icons/icon-128.png',
        title: 'Notification Title',
        message: 'This is a message for the notification.',
    });
});