memo_template: add new article-class memo template

Replaces the assignment_template with a memo-format template based
on the article class. The look-and-feel is ported from the old
cdsc-memo chapterstyle in cdsc-memoir.sty: a single-line "TITLE
[hfill] AUTHOR" header and sans-serif uppercase section headings.

Like the migrated paper_template, this builds with lualatex and
produces a tagged, PDF/UA-2 compliant PDF. verapdf --flavour ua2:
0 failures, 1723 passed rules.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

memo_template/Makefile

@@ -0,0 +1,30 @@
+#!/usr/bin/make
+
+all: $(patsubst %.tex,%.pdf,$(wildcard *.tex)) 
+
+# use the following section for Rnw/knitr documents
+# all: $(patsubst %.Rnw,%.pdf,$(wildcard *.Rnw))
+# %.tex: %.Rnw
+#	Rscript -e "library(knitr); knit('$<')"
+
+%.pdf: %.tex 
+	latexmk -f -lualatex $<
+
+clean: 
+	latexmk -C *.tex
+	rm -f *.tmp *.run.xml
+	rm -f vc
+	rm -f *.bbl
+	# the following lines are useful for Rnw/knitr
+	# rm -rf cache/ figure/
+	# rm -f *.tex
+
+viewpdf: all
+	evince *.pdf
+
+vc:	resources/vc-git
+
+pdf: all
+
+.PHONY: clean all
+# .PRECIOUS: %.tex