made section templates more flexible

Makefile

@@ -1,4 +1,4 @@
-TOPDIR :::= $(PWD)
+TOPDIR ::= $(shell pwd)
 build_dir ::= $(TOPDIR)/build
 config_dir ::= $(TOPDIR)/config
 docker ::= podman
@@ -31,8 +31,6 @@ build_docker_image:
 	$(docker) build -t songsheet_generator .
 pull_docker:
 	$(docker) pull gitea.leopold.fajtak.at/leopold/songsheet_generator:latest
-build_in_docker:
-	$(docker) run -v `pwd`:/data songsheet_generator make -j all
 tex_deps ::= $(template_dir)/variables.tt $(config_dir)/qr_codes.csv $(config_dir)/variables.tt $(dynamic_deps)
 songsheet.tex: $(template_dir)/songsheet.tt $(tex_deps) $(template_dir)/header.tt $(template_dir)/head.tt $(template_dir)/footer.tt
 %.tex: build $(tex_deps)