add missing ipynb files to Makefile

docs/Makefile

@@ -29,9 +29,12 @@ help:
 	cp ../examples/notebook_luminosity_function_binaries.ipynb source/
 	cp ../examples/notebook_HRD.ipynb source/
 	cp ../examples/notebook_common_envelope_evolution.ipynb source/
-	
+	cp ../examples/notebook_BHBH.ipynb source/
+	cp ../examples/notebook_massive_remnants.ipynb source/
+	cp ../examples/notebook_solar_system.ipynb source/
+
 	# Copy the badges
 	cp -r ../badges/ source/
-	
+
 	# actually run the sphinx stuff
 	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)