update readme, mod card

.modkitignore

@@ -0,0 +1,30 @@
+# Files that stay in the repo and out of the distributed package.
+# Exact relative paths, one per line -- modkit matches literally, no globs.
+
+# The SDK suite and the probes it grew out of. A shipped test that requires
+# an engine module reads as a private require against the archive
+# (CONTRIBUTING-mods.md "What the PR must contain", 2).
+tests/dramatic_shape_test.lua
+tests/voxel_anim_probe.lua
+tests/voxel_door_probe.lua
+tests/voxel_mem_probe.lua
+tests/voxel_perf_probe.lua
+tests/voxel_pipeline_probe.lua
+tests/voxel_seam_shots.lua
+tests/voxel_shadow_probe.lua
+tests/voxel_survey.lua
+tests/voxel_void_probe.lua
+
+# Authoring tools. These run by hand on a machine that has imported its own
+# ROM, read the local cache, and emit assets/voxels/*.lua; the carved models
+# are what a player installs, the carving is not.
+tools/build_voxels.py
+tools/building_images.py
+tools/building_voxels.py
+tools/voxel-survey.md
+assets/docs/buidling_to_voxel/sprite_extract.py
+assets/docs/buidling_to_voxel/voxel_build_verify.py
+
+# assets/docs/**.md stays in: data/voxel_heights.lua points a modder at the
+# building catalogue, and the methodology is where the geometry's provenance
+# is written down.