chore: add main to phony

Signed-off-by: Vitor Mattos <vitor@php.rio>

Author: vitormattos

docs/Makefile

@@ -19,7 +19,7 @@
 # %: Makefile
 # 	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
 
-.PHONY: user admin dev all
+.PHONY: main user admin dev all
 
 main:
 	sphinx-autobuild --port 0 /app/docs/main /app/_build