chore: fix make caching

Author: gruhn

Makefile

@@ -1,18 +1,20 @@
-.PHONY: clean
+.PHONY: all
 
-docs: dist equiv-checker.html tsconfig.build.json
+all: Makefile node_modules/.stamp docs/.stamp dist/.stamp
+
+####################################################
+
+docs/.stamp: dist/.stamp equiv-checker.html tsconfig.build.json
 	npx typedoc --tsconfig tsconfig.build.json
 	cp -r dist/ docs/dist/
 	cp equiv-checker.html docs/
+	touch $@
 
-dist: src node_modules tsconfig.build.json
+dist/.stamp: tsconfig.build.json src/*.ts
 	npx tsc --project tsconfig.build.json
 	npx tsc-alias
+	touch $@
 
-node_modules: package-lock.json
+node_modules/.stamp: package-lock.json
 	npm ci
-
-####################################################
-
-clean:
-	rm -rf dist/ docs/
+	touch $@