Add prototype notes compilation script.

books/compile_notes/compile.sh
	-Add an unfinished script to compile all markdown notes to
	either HTML or LaTeX PDF formats.
	-Add basic argument handling.
Move argument handling to handler_user_args().

books/compile_notes/compile.sh
	-Move `misuse_exit` and verbose argument-handling `case`
	statement to a new function, `handler_user_args()`.
	-Call it from top-level scope.
Define compile_html() and compile_latex().

books/compile_notes/compile.sh
	-Define `compile_html()` and `compile_latex()`, and call them
	from `handler_user_args()` for respective arguments.
Document all the things (compile.sh).

books/compile_notes/compile.sh
	-Add documentation comments to file header and all functions.
Handle script execution from other dirs.

books/compile_notes/compile.sh
	-Make all of the script's resource paths (ie, paths to the
	template files, etc. used by `pandoc`) absolute, to allow
	execution from directories that aren't its own.
Add supplementary pandoc template files.

books/compile_notes/
(header.tex, (markdown, pygments).css, template.html)
	-Add all templating files required by `pandoc`.
	-Control styling/layout in both the HTML and LaTeX PDFs.
Document the PDF utility in the books/ README.

books/README.md
	-Document the `compile_notes/compile.sh` utility in the `books/`
	README, as it'll be applicable for all contained notes.
Merge branch 'books/nand2tetris.compile_notes' into books/nand2tetris

books/compile_notes/
	-Write a simple utility to compile my notes, all of which will
	be written in markdown format with embedded LaTeX, to either
	LaTeX or HTML style PDFs.