Add a README

Closes #10.

README.md

@@ -0,0 +1,33 @@
+This repository provides a checklist of things to do, complete, & achieve in
+the video game *The Legend of Zelda: Breath of the Wild*.  The checklist data
+is stored as JSON in [`checklist.json`](/checklist.json) alongside additional
+files for converting it to a printable PDF file.
+
+
+Building the PDF
+================
+
+Requirements:
+
+- GNU Make
+- TeX Live
+- Python 3
+
+Run `make` in a clone of this repository to produce a `checklist.pdf` file that
+can then be printed and checked-off the old-fashioned way.
+
+
+Conventions in the PDF Checklist
+================================
+
+- Items in *italics* (except for shrine trial names) are either DLC or acquired
+  via amiibo.
+
+- Next to the checkbox for each shrine is a treasure chest icon that is
+  intended to be checked off when the player has looted all chests in the given
+  shrine.
+
+- In the "Hyrule Compendium" section, entries that are present in both normal
+  mode and Master Mode have the numbers for each mode listed, with the Master
+  Mode number in **bold**.  Entries that are only present in Master Mode have
+  only one number listed, with both it and the entry name in **bold**.