[Feature] Make Jinja {% docs %} optional in markdown files

[matthieucan]

Is this your first time submitting a feature request?

• I have read the expectations for open source contributors
• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing dbt functionality, rather than a Big Idea better suited to a discussion

Describe the feature

Markdown documentation files often take the following form:

my_model.md

{% docs my_model %}
This is documentation
{% enddocs %}

This is redundant, given the file name convention: my_model.md naturally refers to the model my_model, just like my_model.sql does.

It would be neat to make the Jinja block {% docs %} optional:

my_model.md

This is documentation

This would be consistent with SQL files.

Additionally, {% docs %} is not properly rendered in IDEs, as Jinja is not expected by default in markdown files.

A suggestion to not break any backwards compatibility:

• Not using {% docs %} is optional
• Any markdown file my_model.md is made available for use as description: {{ doc('my_model') }} if and only if documentation for my_model is not defined elsewhere.

Describe alternatives you've considered

No response

Who will this benefit?

Everyone writing docs.

Are you interested in contributing this feature?

Yes

Anything else?

No response