update Readme before publishing

README.md

@@ -1,12 +1,23 @@
-# Example "freewheeling" app that can be modified without being restarted
+# A little tool for sports cross-tables
 
-Running this repo in isolation won't be very helpful. If you haven't yet,
-first check out [the driver app](https://git.sr.ht/~akkartik/driver.love).
-This repo is a template you can copy to create your own live apps that juggle
-text editor widgets. The editors support copy/paste, search, infinite undo,
-etc. You can't modify editor functionality live (yet?).
+All-play-all tournaments often summarize results using a simplistic table of
+wins/losses/points. It is all you need at the end when you're picking the
+qualifiers for the next stage, but it's not very useful _while a tournament is
+in progress_. Some examples of questions it can't answer:
 
-[Some reference documentation on how to create your own apps.](reference.md)
+* Have their been any upsets?
+* Are there any differences in opponents so far? If team A has already played
+  all its lower-seeded opponents but team B has not, that's important.
+
+For questions like these, and also for running what-if scenarios, the ideal
+format is a cross-table that shows each team along both the rows and the
+columns, and summarizes the outcome of each encounter.
+
+The big challenge to maintaining a cross-table by hand is re-sorting it. When
+the rows move around, the columns must do so as well. This tool automates the
+sorting.
+
+![demo showing how to add new results and how to re-sort the cross-table](assets/1.gif)
 
 This repo is an example of a [Freewheeling App](http://akkartik.name/freewheeling),
 designed above all to be easy to run, easy to modify and easy to share.
@@ -17,7 +28,18 @@ Install [LÖVE](https://love2d.org). It's just a 5MB download, open-source and
 extremely well-behaved. I'll assume below that you can invoke it using the
 `love` command, but that might vary depending on your OS.
 
-Run this app from the terminal, [passing its directory to LÖVE](https://love2d.org/wiki/Getting_Started#Running_Games)
+Run this app from the terminal, [passing its directory to LÖVE](https://love2d.org/wiki/Getting_Started#Running_Games),
+passing in a file containing results to show. The file `results` demonstrates
+the expected format. To try it out from this directory:
+
+    ```
+    $ love . results
+    ```
+
+Try clicking around. Your changes will be saved back to `results`.
+
+If you don't pass in a file you'll see some example data. You can still modify
+it, but it won't be persisted.
 
 ## Hacking