Use correct title in exif data

manuscrit/Makefile

@@ -8,6 +8,7 @@ MAIN_PDF=$(BUILD_DIR)/main.pdf
 PRINTOUT_PDF=$(BUILD_DIR)/main-printout.pdf
 ALL=$(CLEANED_PDFS)
 REV_FILE=$(BUILD_DIR)/version
+TITLE_EN=$(shell cat meta/title-en.txt)
 
 all: _setup $(ALL)
 
@@ -26,7 +27,7 @@ $(CLEANED_PDFS):
 	exiftool -all:all= \
 		-Version="$(shell bin/version.sh)" \
 		-Author="Théophile Bastian" \
-		-Title="Performance study: identifying bottlenecks by means of sensitivity analysis" \
+		-Title="$(TITLE_EN)" \
 		"$@"
 	@ pdffonts "$@" | grep -q '   no' && echo -e "\033[0;1;31mSOME FONTS NOT EMBEDDED\033[0m" || true
 	@ !(pdffonts "$@" | grep -q '   no')