Provide an intial README describing what this is and why it's done this way.

README.md

@@ -1,3 +1,45 @@
-# dichotomorse
 
-Tools for learning Morse Code using a dichotomous arrangement.
+Tables commonly depict the correspondence between the letters of the English
+alphabet and the dots-and-dashes combinations for Morse Code.
+
+Many times, these are arranged in alphabetical order. 
+
+Alas, that arrangement obscures the logic of the assignments and in turn
+makes it less obvious how one might go about learning them. 
+
+In short, the assignments are made so that the simplest combinations
+represent the most frequently-used letters. 
+
+The English letter E is the most commonly used, so it gets represented by
+the simplest symbol: A single dot.
+
+Similarly, T is the most common consonant, and the second-most common letter
+overall, so it gets the next simplest symbol: A single dash.
+
+And so it goes. 
+
+The so-called **dichotomous** key shows these correspondences by building up
+from a single dot or dash by adding either a dot or dash to the end as one
+moves through the table. 
+
+In the way I've drawn them here, moving one column to the right means adding
+one more dot or dash. If one moves to the right and up, one adds a dot. If
+one moves to the right and down, one adds a dash.
+
+This repository contains four files. The most complete one contains the
+entirety of the English alphabet as well as the Morse Code for each letter.
+The simplest file is an empty grid with the same layout. Then there is one
+file containing letters, but no code. The remaining file contains code, but
+no letters. 
+
+The incomplete files are meant to be used as practice pads: One
+can try filling them out, either by memorizing progressively where letters
+go in the grid (perhaps using various mnemonics) or by following the logic
+of the dichotomous key to build up the Morse Code representations.
+
+These files are stored in Flat XML spreadsheet format as saved by
+LibreOffice (**.fods**) in the hopes that the files can be put under version
+control in a way that makes any changes at least somewhat human-readable. 
+
+
+