Functions for the export to structurizr.

Functions to read the overarch input models from filesystem.

Functions to read and build the working model from overarch input models.
   
The built model is a map with the following keys

| Key                     | Description 
|-------------------------|-------------
| **Relation keys**       | 
| :nodes                  | the set of all nodes
| :relations              | the set of all relations
| :views                  | the set of views
| :themes                 | the set of themes
| **Index keys**          | 
| :id->element            | a map from id to element (nodes, relations and views)
| :id->parent-id          | a map from id to parent node id
| :id->children           | a map from id to a vector of contained nodes (deprecated)
| :referrer-id->relations | a map from id to set of relations where the id is the referrer (:from)
| :referred-id->relations | a map from id to set of relations where the id is referred (:to)
| **Problem keys**        | 
| :problems               | the set of problems found during model building

The input model is transformed by
* computing missing ids, if possible
* converting the node hierarchies to :contained-in relations
   

Functions for reading and building models and setting the repository state.
The multimethods should be implemented by specific readers.

Functions to export views to GraphViz.

Functions to export views to markdown.

Functions to export views to PlantUML.

Functions to render PlantUML C4 diagrams for architecture and deployment views.

Functions to render PlantUML diagrams for UML views.

Template Engine implementation based on Comb templates.

Public API with useful functions on top of the model for use in templates. (Not yet stable!)

Public API with useful functions on top of the view for use in templates. (Not yet stable!)

Functions for the command line interface of overarch.