Update binary size info in README.md

[no1wudi]

The size info is from bloaty, which is a tool to measure binary size. With WAMR intergrated to NuttX with essential features.

Example usage and output (WAMR stuff only):

➜  sim bloaty -s file nuttx/nuttx -d compileunits --source-filter wamr
    FILE SIZE        VM SIZE
 --------------  --------------
  13.1%   108Ki  19.4%  14.6Ki    wamr/core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/posix.c
  12.2%   100Ki   0.1%      50    wamr/core/iwasm/common/wasm_c_api.c
  10.6%  87.1Ki   8.7%  6.54Ki    wamr/core/iwasm/common/wasm_runtime_common.c
   9.2%  76.1Ki  12.6%  9.45Ki    wamr/core/iwasm/aot/aot_loader.c
   8.9%  73.6Ki  12.5%  9.38Ki    wamr/core/iwasm/libraries/libc-wasi/libc_wasi_wrapper.c
   7.1%  58.7Ki   9.0%  6.79Ki    wamr/core/iwasm/aot/aot_runtime.c
   3.6%  29.3Ki   5.6%  4.21Ki    wamr/core/iwasm/libraries/libc-builtin/libc_builtin_wrapper.c
   3.2%  26.2Ki   3.6%  2.73Ki    wamr/core/shared/platform/common/posix/posix_socket.c
   2.9%  24.0Ki   2.7%  2.01Ki    wamr/core/iwasm/common/wasm_memory.c
   2.8%  23.2Ki   2.3%  1.74Ki    wamr/core/iwasm/common/wasm_application.c
   2.6%  21.5Ki   3.3%  2.46Ki    wamr/core/shared/platform/common/posix/posix_file.c
   2.5%  20.4Ki   1.9%  1.45Ki    wamr/core/iwasm/common/wasm_native.c
   2.4%  20.0Ki   2.0%  1.51Ki    wamr/core/iwasm/aot/arch/aot_reloc_riscv.c
   2.1%  17.3Ki   1.6%  1.20Ki    wamr/core/iwasm/common/wasm_shared_memory.c
   2.0%  16.4Ki   2.4%  1.81Ki    wamr/core/shared/mem-alloc/ems/ems_alloc.c
   1.9%  15.9Ki   2.4%  1.81Ki    wamr/product-mini/platforms/nuttx/main.c
   1.7%  13.8Ki   1.4%  1.05Ki    wamr/core/iwasm/aot/aot_intrinsic.c
   1.5%  12.2Ki   0.4%     312    wamr/core/iwasm/common/wasm_exec_env.c
   1.4%  11.8Ki   0.8%     618    wamr/core/shared/platform/common/posix/posix_thread.c
   1.0%  8.20Ki   1.2%     952    wamr/core/shared/utils/bh_hashmap.c
   0.9%  7.52Ki   0.8%     636    wamr/core/shared/utils/bh_vector.c
   0.9%  7.46Ki   0.8%     618    wamr/core/shared/mem-alloc/ems/ems_kfc.c
   0.8%  6.89Ki   1.0%     744    wamr/core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/blocking_op.c
   0.8%  6.65Ki   0.5%     356    wamr/core/shared/platform/nuttx/nuttx_platform.c
   0.5%  4.25Ki   0.4%     316    wamr/core/shared/utils/bh_common.c
   0.4%  3.70Ki   0.3%     248    wamr/core/shared/utils/bh_log.c
   0.4%  3.52Ki   0.4%     330    wamr/core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/random.c
   0.4%  3.07Ki   0.1%      40    wamr/core/shared/mem-alloc/mem_alloc.c
   0.3%  2.52Ki   0.3%     196    wamr/core/shared/utils/uncommon/bh_read_file.c
   0.3%  2.36Ki   0.3%     216    wamr/core/shared/platform/common/posix/posix_clock.c
   0.3%  2.27Ki   0.1%     106    wamr/core/shared/utils/bh_list.c
   0.2%  1.91Ki   0.6%     430    wamr/core/shared/platform/common/libc-util/libc_errno.c
   0.2%  1.78Ki   0.1%      94    wamr/core/iwasm/libraries/libc-wasi/sandboxed-system-primitives/src/str.c
   0.2%  1.73Ki   0.0%       6    wamr/core/iwasm/common/wasm_blocking_op.c
   0.2%  1.42Ki   0.1%      74    wamr/core/shared/utils/bh_bitmap.c
   0.1%  1.02Ki   0.1%      82    wamr/core/shared/platform/common/posix/posix_time.c
   0.1%     751   0.2%     138    wamr/core/iwasm/common/arch/invokeNative_riscv.S
 100.0%   823Ki 100.0%  75.1Ki    TOTAL

[wenyongh]

LGTM