Add 'History of the Theravāda' content to the site

[khemarato]

This is a task to publish the History of the Theravāda folder on Google Drive as a new bibliography/tag on the site.

This includes adding all the course: theravada-roots content.
For more information on how to add content from Drive to the website, see the content data entry guide.

Steps needed to accomplish this:

• Add the tag as a draft to _tags/
  • Done! See the draft tag here
• Add suttas from the folder to the site
• Add OpenAlex academic articles in the folder to the site
• Add all other content from the public drive folder
• Add any copyrighted content (e.g. YouTube links, books, or podcasts) not shared directly in the public folder
• Add a draft set of images
• Add a description
• Add an image caption
• Audit tag content for:
  • Meeting the diversity quotas
  • Weeding content that shouldn't be included
  • Harmony of description, images, and content
• Productionize images
• Publish the tag
• Announce the tag on the blog/newsletter