Set up gift-guide as its own repo with a pandoc+weasyprint build pipeline

Converts the lead-magnet PDF from a Google Slides export into an editable
markdown template, styled to match reground.org's dark theme, with a
Makefile convention (make partners/<slug>.pdf) for producing per-partnership
customized versions.

Makefile

@@ -0,0 +1,17 @@
+PANDOC     = pandoc
+PDF_ENGINE = weasyprint
+TEMPLATE   = template.html
+CSS        = style.css
+PARTNERS   = $(patsubst %.md,%.pdf,$(wildcard partners/*.md))
+
+.PHONY: all clean
+
+all: template.pdf $(PARTNERS)
+
+# style.css is linked directly from template.html (not passed via --css),
+# but listed here so editing it triggers a rebuild of every PDF.
+%.pdf: %.md $(TEMPLATE) $(CSS)
+	$(PANDOC) $< -o $@ --template=$(TEMPLATE) --pdf-engine=$(PDF_ENGINE) --standalone
+
+clean:
+	rm -f template.pdf partners/*.pdf