docs: add the dsperate-headless dsi boot blob

dsperate-headless reads a 0x154-byte console data blob through --dsi-boot and stops on any other size. The flag has no default, so the name is a label. Without it the bytes come from the NAND's TWLCFG and HWINFO files, are generated for DSiWare run without a NAND, or stay zero in card mode.

emulators/dsperate.yml

@@ -136,6 +136,16 @@ files:
     note: "Read only by --dsi-mode and NAND title shortcuts. DSiWare run from the game list does without it. Opened read-only, rejected without the \"DSi eMMC CID/CPU\" footer."
     source_ref: "src/frontend/sdl/main.cpp:1153-1166, src/frontend/sdl/main.cpp:1331-1337, src/core/nds_dsi.cpp:112-118, src/core/io/dsi_sd.cpp:105-138"
 
+  - name: "dsi_boot.bin"
+    system: nintendo-dsi
+    required: false
+    size: 340
+    validation: [size]
+    found_by: content
+    description: "DSi console data blob"
+    note: "Read only by dsperate-headless, through --dsi-boot, which has no default, so the name is a label. A file of any size other than 0x154 bytes stops the run. The blob is TWLCFG bytes 0x88-0x1AF, HWINFO_N bytes 0x88-0x9B and HWINFO_S bytes 0x88-0x9F, copied to 0x02000400, 0x02000600 and 0x02FFFD68 when a DSi title starts. Without it the same bytes are read from shared1/TWLCFG0.dat or TWLCFG1.dat (the higher save count at byte 0x81) and sys/HWINFO_N.dat and sys/HWINFO_S.dat of an attached NAND, generated for DSiWare run without a NAND, and left zero in card mode."
+    source_ref: "src/frontend/headless/main.cpp:304, src/frontend/headless/main.cpp:386, src/frontend/headless/main.cpp:508, src/core/nds_dsi.cpp:107-111, src/core/nds_dsi.cpp:294, src/core/nds_dsi.cpp:340-343, src/core/nds_dsi.cpp:454-464, src/core/io/dsi_nand_launch.cpp:147-167, src/core/io/dsi_nand_synth.cpp:114-120"
+
   - name: "TWLFontTable.dat"
     system: nintendo-dsi
     required: false