rename target run-bios -> run

Rsconscript

@@ -100,6 +100,6 @@ EOF
     env.depends("#{env.build_root}/hos.elf", "src/link.ld")
     env.Disassemble("^/hos.elf.txt", "^/hos.elf")
     env.EfiImage("build/hos-efi.img", %w[^/hos.elf])
-    env.BiosImage("build/hos-bios.img", %w[^/hos.elf])
+    env.BiosImage("build/hos.img", %w[^/hos.elf])
   end
 end