docs: updates to use DML and other changes (#7834)

- Change existing data model guides and add new ones for DML
- Change module's docs around service factory + remove guides that are now necessary
- Hide/remove all mentions of module relationships, or label them as coming soon.
- Change all data model creation snippets to use DML
- use `property` instead of `field` when referring to a data model's properties.
- Fix all snippets in commerce module guides to use new method suffix (no more main model methods)
- Rework recipes, removing/hiding a lot of sections as a lot of recipes are incomplete with the current state of DML.


### Other changes

- Highlight fixes in some guides
- Remove feature flags guide
- Fix code block styles when there are no line numbers.

### Upcoming changes in other PRs

- Re-generate commerce module references (for the updates in the method names)
- Ensure that the data model references are generated correctly for models using DML.
- (probably at a very later point) revisit recipes

www/apps/book/app/advanced-development/modules/link-modules/page.mdx

@@ -14,7 +14,7 @@ For example, Medusa has a link module that defines a relationship between the Pr
 
 ![Diagram showcasing the link module between the Product and Pricing modules](https://res.cloudinary.com/dza7lstvk/image/upload/v1709651569/Medusa%20Resources/product-pricing_vlxsiq.jpg)
 
-Link modules provide more flexibility in managing relationships between modules while maintaining module isolation. The Medusa application only creates the link tables when both modules are available.
+Link modules create the relationship between modules while maintaining module isolation. The Medusa application only creates the link tables when both modules are available.
 
 <Note type="soon">