docs: Adding periphery rules.

Updates and documentation originally improved and then release by
Kevin Kelly <kevin.kelley@skywatertechnology.com> to Google for imported
into the docutils RST format by Tim 'mithro' Ansell <tansell@google.com>.

Signed-off-by: Kevin Kelley <kevin.kelley@skywatertechnology.com>
Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>
diff --git a/docs/Makefile b/docs/Makefile
index 8e28876..db06a05 100644
--- a/docs/Makefile
+++ b/docs/Makefile
@@ -42,6 +42,13 @@
 
 .PHONY: help livehtml Makefile
 
+# Generate the rules/periphery-rules.rst from CSV files in rules/periphery/
+$(wildcard rules/periphery/*): | $(CONDA_ENV_PYTHON)
+	true
+
+rules/periphery-rules.rst: $(wildcard rules/periphery/*) | $(CONDA_ENV_PYTHON)
+	$(IN_CONDA_ENV) cd rules/periphery; ./periphery-split-csv.py > /dev/null
+
 # Various automated fixups that can be run
 fixup:
 	# Make sure it is SkyWater