Base theme updates

[jenningsanderson]

Description

Adds more OSM tags — species, genus to the source_tags for the land type which includes trees.

Adds OSM's layer tag as Overture's level tag.

Reference

Testing

Brief description of the testing done for this change showing why you are confident it works as expected and does not introduce regressions. Provide sample output data where appropriate.

TODO.

Checklist

Checklist of tasks commonly-associated with schema pull requests. Please review the relevant checklists and ensure you do all the tasks that are required for the change you made.

1. [N/A] Add relevant examples.
2. [N/A] Add relevant counterexamples.
3. [N/A] Update any counterexamples that became obsolete. For example, if a counterexample uses property A but is not intended to test property A's validity, and you made a schema change that invalidates property A in that counterexample, fix the counterexample to align it with your schema change.
4. [N/A] Update in-schema documentation using plain English written in complete sentences, if an update is required.
5. [N/A] Update Docusaurus documentation, if an update is required.
6. [N/A] Review change with Overture technical writer to ensure any advanced documentation needs will be taken care of, unless the change is trivial and would not affect the documentation.

Documentation Website

Update the hyperlink below to put the pull request number in.

Docs preview for this PR.

[skmoore]

Can we also add height, est_height, min_height, diameter_crown, leaf_type, leaf_cycle, taxon, taxon:species, taxon:cultivar, and denotation. We currently use all of these tags to create our 3d trees layer from Daylight.