some clean up - move dos unpacker, fix arm32 unpacker formatting

README.md

@@ -20,7 +20,7 @@ is both about twice as fast and smaller than the Shrinkler unpacker.
 The release includes a reference c unpacker, as well as some optimized asm unpackers (arm and riscv). The unpckers in
 c_unpacker and asm_unpackers unpack the default upkr compressed format. The z80_unpacker
 is based on some variations to the compressed format. (Use `upkr --z80` to select those variations.)
-An optimized x86 (DOS) unpacker is currently being worked on out of tree.
+The 16 bit dos unpacker also uses some variations. (`upkr --x86`)
 
 ## Usage
 

dos_unpacker/readme.txt

@@ -0,0 +1,13 @@
+16 bit DOS executable stubs
+---------------------------
+
+by pestis and TomCat
+
+unpack_x86_16_DOS.asm:
+  maximum compatibility, relocates unpacked code to normal start address
+unpack_x86_16_DOS_no_relocation.asm:
+  saves some bytes by not relocating, unpacked code needs to be assembled to
+  start at 0x3FFE
+unpack_x86_16_DOS_no_repeated_offset.asm:
+  removes support for repeated offsets, potentially at the cost of some compression ratio.
+  most likely only a win in very narrow circumstances around the 1kb mark