Issue #1148 api changelog (#1149)

Fixes #1148

# Description
- Ensures API package is added to API reference
- Adds explicit reference to API Package
- Enables init validation of API Package, which was for some reason
moved outside object.

# Checklist
- [x] Links to correct issue
- [x] Update changelog, if changes affect users
- [x] PR title starts with ``Issue #nr``, e.g. ``Issue #737``
- [ ] Unit tests were added
- [ ] **If feature added**: Added/extended example

docs/api/changelog.rst

@@ -212,8 +212,9 @@ Added
 ~~~~~
 - Developer environment: Added pixi environment ``interactive`` to interactively
   run code. Can be useful to plot data.
-- An API package was added. It can be added to both flow and transport models, and its 
-  presence allows users to interact with libMF6.dll through its API.
+- :class:`imod.mf6.ApiPackage` was added. It can be added to both flow and
+  transport models, and its presence allows users to interact with libMF6.dll
+  through its API.
 - Developer environment: Empty python 3.10, 3.11, 3.12 environments where pip
   install and import imod can be tested.
 

docs/api/mf6.rst

@@ -66,6 +66,7 @@ Flow Packages
 .. autosummary::
     :toctree: generated/mf6
 
+    ApiPackage
     Buoyancy
     ConstantHead
     Drainage
@@ -91,6 +92,7 @@ Transport Packages
 .. autosummary::
     :toctree: generated/mf6
 
+    ApiPackage
     AdvectionCentral
     AdvectionTVD
     AdvectionUpstream

imod/mf6/api_package.py

@@ -5,10 +5,6 @@
     DTypeSchema,
 )
 
-_init_schemata = {
-    "maxbound": [DTypeSchema(np.integer)],
-}
-
 
 class ApiPackage(Package):
     """
@@ -46,6 +42,9 @@ class ApiPackage(Package):
 
     _pkg_id = "api"
     _template = Package._initialize_template(_pkg_id)
+    _init_schemata = {
+        "maxbound": [DTypeSchema(np.integer)],
+    }
 
     def __init__(
         self,