[chore] Fix md generation commands in makefile (open-telemetry#865)

Author: lmolkova

Makefile

@@ -95,13 +95,13 @@ yamllint:
 .PHONY: table-generation
 table-generation:
 	docker run --rm -v $(PWD)/model:/source -v $(PWD)/docs:/spec \
-		otel/semconvgen:$(SEMCONVGEN_VERSION) -f /source markdown
+		otel/semconvgen:$(SEMCONVGEN_VERSION) -f /source markdown -md /spec
 
 # Check if current markdown tables differ from the ones that would be generated from YAML definitions
 .PHONY: table-check
 table-check:
 	docker run --rm -v $(PWD)/model:/source -v $(PWD)/docs:/spec \
-		otel/semconvgen:$(SEMCONVGEN_VERSION) -f /source markdown -md /spec
+		otel/semconvgen:$(SEMCONVGEN_VERSION) -f /source markdown -md /spec --md-check
 
 .PHONY: schema-check
 schema-check: