Add a directory for proposed specifications

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/docs/proposed/Makefile b/docs/proposed/Makefile
new file mode 100644
index 0000000..97f288a
--- /dev/null
+++ b/docs/proposed/Makefile
@@ -0,0 +1,21 @@
+PANDOC = pandoc
+
+default: all
+
+all_markdown = \
+	       # This line is intentionally left blank
+
+html: $(all_markdown:.md=.html)
+pdf: $(all_markdown:.md=.pdf)
+all: html pdf
+
+.SUFFIXES:
+.SUFFIXES: .md .html .pdf
+
+.md.html:
+	$(PANDOC) -o $@ $<
+.md.pdf:
+	$(PANDOC) -o $@ $<
+
+clean:
+	rm -f *.html *.pdf