docs: initialize app for vertical tagging in course-discovery and add an ADR for it

[AfaqShuaib09]

This PR adds the ADR for Vertical Tagging feature and initialize a separate app for it in discovery

[bradenmacdonald]

This ADR is a bit confusing because in a course context, "Vertical" usually refers to a unit, but I take it that here it's referring to something like "subject area" ?

Are you familiar with the Taxonomy and Tagging functionality from openedx_tagging and the taxonomy features in Studio? I'm wondering if you can just create a business-oriented "Vertical Taxonomy" and then use openedx_tagging to tag the courses as needed.

Example taxonomy view in Studio:

[DawoudSheraz]

Hey @bradenmacdonald, thanks for your input. Adding my responses below.

This ADR is a bit confusing because in a course context, "Vertical" usually refers to a unit, but I take it that here it's referring to something like "subject area" ?

Yes, this vertical refers to subject area but from a business point of view. While I agree that Vertical refers to a unit, that is primarily true in studio/cms terms. course-discovery does not follow all the studio conventions (such as course vs course run concept). However, we can think of a different name to avoid any potential conflicts for future (at least until the DEPR is not in place).

Are you familiar with the Taxonomy and Tagging functionality from openedx_tagging and the taxonomy features in Studio? I'm wondering if you can just create a business-oriented "Vertical Taxonomy" and then use openedx_tagging to tag the courses as needed.

This is something we are looking into. At the moment, it is not certain if we go for openedx_tagging as it is, given that it seems to be designed with platform in mind. Once we have that, this vertical tagging will be a candidate to be "mapped" as a taxonomy.

[DawoudSheraz]

please add the app in INSTALLED_APPS before the merge.

[zawan-ila]

[suggest] Bullet points and some rephrasing
1. Introduce a structured approach to categorizing courses by aligning them with specific business objectives
2. Enable more effective classification of courses based on verticals, ensuring that courses can be easily discovered and grouped according to strategic priorities, thereby improving overall discoverability.