docs: Enable Google Analytics and implement a pop-up cookie consent banner

[skoech]

Description

This PR enables Google Analytics (GA) for MicroCeph documentation. But to use GA on a Read the Docs (RTD) project, it is required to implement a consent collection mechanism before placing tracking cookies on a reader's device. The standard way we collect user consent is by using the web team’s cookie policy banner, which is visually consistent across our Ubuntu and Canonical properties. This is now also available for RTD projects.

The PR adds:

• HTML templates: header.html that inserts the GA tracking tag onto each page, and footer.html that provides a link for users to change their data collection preferences. The files are available to download from the RTD-cookie-banner repository. The README file of the cookie banner repository contains the implementation instructions.
• Configuration to support required template and static files

When this PR is merged, the cookie banner will be shown to our users, and GA collection will begin as soon as a user accepts tracking cookies.

Type of change

• New feature (non-breaking change which adds functionality)
• Documentation update (change to documentation only)

How has this been tested?

• I have built the documentation locally and verified that the cookie banner pops up when first visiting the site, using these commands (screenshot shown below):

cd docs

make clean
make install
make run

Note

You may need to clear your browser cache for changes to take effect, or use Incognito mode.

---

• I have tested the tracker settings and verified that the toggles work as expected. I've done this by fiddling with the configuration choices under Manage your tracker settings:

Contributor checklist

Please check that you have:

• self-reviewed the code in this PR
• added code comments, particularly in less straightforward areas
• checked and added or updated relevant documentation
• checked and added or updated relevant release notes
• added tests to verify effectiveness of this change

[geoffreynyaga]

@skoech

I have reviewed the PR and also run it locally.
The cookie banner is working and I can customize the available options. The code changes also follow the provided guidance from the starter pack repo.

All good!

[lmlg]

lgtm!

[skoech]

Thanks, @geoffreynyaga and @lmlg!