[CT-3237] Display compiled metric code in docs

[siljamardla]

Describe the feature

Related to #467
As with dbt models, I would expect to be able to see the compiled code of a metric in the dbt docs. This used to be displayed with dbt-metrics if I remember correctly. At the moment the docs page for a metric is quite useless, it only displays the name, description, tags and metadata but nothing about how the metric gets calculated or what exactly is its definition.

Describe alternatives you've considered

At the moment, the only option to make docs more useful is to manually run a MetricFlow query with --explain flag for each metric and manually include the output into the description.

Additional context

No

Who will this benefit?

Anyone who needs to understand the definition of the metric.

Are you interested in contributing this feature?

Sure

[github-actions]

This issue has been marked as Stale because it has been open for 180 days with no activity. If you would like the issue to remain open, please comment on the issue or else it will be closed in 7 days.

[github-actions]

Although we are closing this issue as stale, it's not gone forever. Issues can be reopened if there is renewed community interest. Just add a comment to notify the maintainers.