Google Analytics Workaround Until pydata_sphinx_theme Fix Released

[erogluorhan]

Closes #105

This PR is intended for using a workaround to get Foundations Book's Google Analytics working until this pydata-sphinx-theme PR gets merged and released.

Brief Explanation of Solution:

• google_analytics_id under html tag in _config.yml is disabled. Instead, templates_path under sphinx tag as a config item into this file.
• In _templates/layout.html, we still extend sphinx_book_theme/layout.html that is the default jupyter-book that we are already using here.
• In that layout file, we are manually adding the Google Analytics snippet as suggested by Google to the extrahead before body.
• The other html files in the _templates folder are just for avoiding build errors.

The source of the locally generated book seems to be correct as follows:

There was a slight difference in the footer of the newly generated book compared to the published one in my local as follows; however, there is no such difference in the generated preview here, so I think we don't need to worry about that?

[github-actions]

🚀 📚 Preview for git commit SHA: 421bf74 at: https://612d35f8d9efcc29d87c61e8--pythia-foundations.netlify.app

[erogluorhan]

Hi @kmpaul , just FYI: I added the Infrastructure group as the reviewer, thinking it may add you, but it didn't add you.

[kmpaul]

Looks great, @erogluorhan! Thanks for doing this!

[kmpaul]

Merge when ready.