Makefile: Rebuild when .py scripts are changed

Makefile

@@ -5,7 +5,7 @@ data/crosswalk.csv:
 	wget https://github.com/codemeta/codemeta/raw/master/crosswalk.csv -O data/crosswalk.csv
 
 # Convert crosswalk.csv to crosswalk.json so Hugo can parse it
-data/crosswalk.json: data/crosswalk.csv
+data/crosswalk.json: scripts/crosswalk_to_json.py data/crosswalk.csv
 	python3 scripts/crosswalk_to_json.py
 
 # properties_description.csv file was only split off from crosswalks.csv starting with
@@ -18,5 +18,5 @@ data/properties_description/v2.0.csv:
 data/properties_description/v%.csv:
 	wget https://github.com/codemeta/codemeta/raw/$*/properties_description.csv -O $@
 
-data/properties_description.json: data/properties_description/v2.0.csv data/properties_description/v3.0.csv
+data/properties_description.json: scripts/properties_to_json.py data/properties_description/v2.0.csv data/properties_description/v3.0.csv
 	python3 scripts/properties_to_json.py