demosplash2023: add some documentation

demos/lovebyte2023/agony_32/README

@@ -0,0 +1,16 @@
+This is just some more Apple II Xdraw (firmware vector drawing).
+
+In this case I wanted to draw short lines, the value for the
+shapetable was $04 $00.  I tried various ways to point to this
+value in a short manner, but even putting it at address $0101 (an
+easy pointer to load into X/Y/A) didn't help with the size.
+
+Eventually I found $0400 in ROM and point to that instead.
+
+I really liked the effect but despite all the effort was not able
+to get it down to the 16-byte category.  If you're lucky you can
+remove the HPOSN call to save 3 bytes, but that depends on random
+RAM contents at boot.
+
+So anyway, in agony after weeks I just kept it at 17 bytes and
+submitted it as a 32-byte demo.

demos/lovebyte2023/blueflame_1k/README

@@ -0,0 +1,34 @@
+BlueFlame, 1k Apple II Hi-res demo presented at Lovebyte 2023
+
+Code by Deater
+Music by MA2E
+ZX02 compression by DMSC
+
+1k entries are difficult as it's so much bitter than 256 bytes so you
+feel like you should be able to do a lot, but at the same time it's
+a lot more work for not much better production.
+
+The shape-table letter motions were the first idea and turned out well.
+It's convenient DEATER and DESIRE share so many letters.  Also thought
+maybe A DEMO or DEMO OVER could be printed but that ended up not being
+necessary.
+
+The "blue flame" is essentially my attempt at the Doom Fire for hi-res.
+It's actually doing the effect on PAGE2 and copying to PAGE1 each frame.
+
+The "static column" effect was a 32-byte effect I had come up with a while
+ago.
+
+The parallax-sierpinski at the beginning was an attempt to do some sort
+of hi-res parallax effect on the Apple II.  Scrolling hi-res is slow at
+the best of times so I was using sierpinski (and) and boxes (xor) to
+make things simpler, and even then the framerate isn't that great.
+
+The music is by MA2E and uses a simple 2-track music tracker I have.
+
+This was compressed with ZX02 compression.  The small ZX02 decompressor
+is around 130 bytes of code, but the music especially compressed more than
+this so it was a win.  It did make size-optimizing difficult as optimizing
+for compression is dificult.  Shaving bytes off the uncompressed code can
+actually make the compressed image bigger.
+

demos/lovebyte2023/ooze_32/README

@@ -0,0 +1,10 @@
+This effect was found when trying to do a fancy screen
+wipe for the "Peasant's Quest" game.
+
+It was surprisingly popular when posted to the Apple II
+Twitter Bot (RIP) so I modified it into a Lovebyte entry.
+
+It's essentially just reading "random" data from the Applesoft ROM
+and drawing it row by row to the screen which looks a bit
+like glitched vertical columns.
+