add chrome.power/keep awake as an api sample

[patrickkettner]

This is an existing extension that was previously hosted on chromium.org. It has
~400k users, but had been orphaned over the years. I took it over to migrate to
Manifest v3. Given we are hosting the code for the Font Settings extension, and
we don't have a chrome.power sample, I thought it made sense to host the code
here.

[oliverdunk]

Left a few comments, let me know when you've tweaked and I can test and approve :)

[oliverdunk]

Left one more comment, otherwise I tested this and it looks good so I'm happy.

[oliverdunk]

One nit, otherwise LGTM.

[NicholaiMM]

Let's make a Chrome extension that allows you to use a menu and hotkeys to insert commonly used text such as intros, commands, and signatures. I found Ganpati internal tool at Google very useful but it's only available to Google employees with an email ending in @google.com

An example of the type of simple signature that could be with a simple dropdown menu when you click the extension is a simple signature you use across multiple sites, such as the following:

Thank you and kind regards,

Nicholai Maro Madias
Network Administrator
‪(727) 370-3006‬
[email protected]