Rework summary.py into a module

process/core/io/plot/summary/__init__.py

@@ -0,0 +1,17 @@
+"""PROCESS summary plotting entry points."""
+
+from process.core.io.plot.summary.api import (
+    create_thickness_builds,
+    main_plot,
+    plot_summary,
+)
+from process.core.io.plot.summary.reporting.constraints import (
+    plot_inequality_constraint_equations,
+)
+
+__all__ = [
+    "create_thickness_builds",
+    "main_plot",
+    "plot_inequality_constraint_equations",
+    "plot_summary",
+]