LuaLaTeX and XeLaTeX not run enough times during docs generation

[juliangilbey]

The documents cannot be processed with plain PDFLaTeX because they have wide UTF-8 characters in them. So I tried using LuaLaTeX instead, but the references were not properly processed. I have located the cause of the problem:

https://github.com/chrislit/abydos/blob/9ec382485394070cca186e9705c30583877dc8e1/docs/Makefile#L157

should instead read:

	$(MAKE) PDFLATEX='latexmk -lualatex' -C $(BUILDDIR)/latex all-pdf

and similarly

https://github.com/chrislit/abydos/blob/9ec382485394070cca186e9705c30583877dc8e1/docs/Makefile#L164

should read

	$(MAKE) PDFLATEX='latexmk -xelatex' -C $(BUILDDIR)/latex all-pdf