Add command for multi-platform image build

[khssnv]

If the user never made multi-platform docker image build, a step 2 of the readme fails at the first RUN directives of the dockerfile with a not obvious error shown under a toggle below. This patch adds multi-platform build support as recommended in docker/buildx#1986, https://docs.docker.com/build/building/multi-platform/#qemu.

Also minor typo fixes.

docker buildx build --platform arm64 --build-arg USE_RVIZ=0 --build-arg SIM=0 --build-arg ROS_DISTRO=humble --build-arg CORE_NUM=10 -f Dockerfile --squash -t khassanov/rae-ros-robot:humble --load .

docker buildx build --platform arm64 --build-arg USE_RVIZ=0 --build-arg SIM=0 --build-arg ROS_DISTRO=humble --build-arg CORE_NUM=10 -f Dockerfile --squash -t khassanov/rae-ros-robot:humble --load .
WARNING: experimental flag squash is removed with BuildKit. You should squash inside build using a multi-stage Dockerfile for efficiency.
[+] Building 2.3s (6/20)                                                                                                                                                             docker:default
 => [internal] load build definition from Dockerfile                                                                                                                                           0.1s
 => => transferring dockerfile: 2.12kB                                                                                                                                                         0.0s
 => [internal] load .dockerignore                                                                                                                                                              0.1s
 => => transferring context: 66B                                                                                                                                                               0.0s
 => [internal] load metadata for ghcr.io/luxonis/rae-base:2023.12.19                                                                                                                           1.5s
 => CACHED [ 1/16] FROM ghcr.io/luxonis/rae-base:2023.12.19@sha256:df6ceda4432b3839da9d737178f0b34628f28012dfbb2d614640885888d8b243                                                            0.0s
 => [internal] load build context                                                                                                                                                              0.1s
 => => transferring context: 10.64kB                                                                                                                                                           0.0s
 => ERROR [ 2/16] RUN apt-get update && apt-get -y install --no-install-recommends     software-properties-common     libusb-1.0-0-dev     python3-colcon-common-extensions     python3-rosde  0.5s
------                                                                                                                                                                                              
 > [ 2/16] RUN apt-get update && apt-get -y install --no-install-recommends     software-properties-common     libusb-1.0-0-dev     python3-colcon-common-extensions     python3-rosdep     build-essential     gpiod     libasound2-dev     ros-humble-cv-bridge     ros-humble-image-transport     ros-humble-image-transport-plugins     ros-humble-rmw-cyclonedds-cpp     gstreamer1.0-plugins-bad     alsa-utils     mpg123     libmpg123-dev     ros-humble-rtabmap-slam     unzip     ffmpeg     ros-humble-image-proc     git     htop     libsndfile1-dev     libsndfile1:
0.395 exec /bin/sh: exec format error
------
Dockerfile:7
--------------------
   6 |     
   7 | >>> RUN apt-get update && apt-get -y install --no-install-recommends \
   8 | >>>     software-properties-common \
   9 | >>>     libusb-1.0-0-dev \
  10 | >>>     python3-colcon-common-extensions \
  11 | >>>     python3-rosdep \
  12 | >>>     build-essential \
  13 | >>>     gpiod \
  14 | >>>     libasound2-dev \
  15 | >>>     ros-humble-cv-bridge \ 
  16 | >>>     ros-humble-image-transport \
  17 | >>>     ros-humble-image-transport-plugins \
  18 | >>>     ros-humble-rmw-cyclonedds-cpp \
  19 | >>>     gstreamer1.0-plugins-bad \
  20 | >>>     alsa-utils \
  21 | >>>     mpg123 \
  22 | >>>     libmpg123-dev \
  23 | >>>     ros-humble-rtabmap-slam \ 
  24 | >>>     unzip \
  25 | >>>     ffmpeg \
  26 | >>>     ros-humble-image-proc \
  27 | >>>     git \
  28 | >>>     htop \
  29 | >>>     libsndfile1-dev \
  30 | >>>     libsndfile1
  31 |     
--------------------
ERROR: failed to solve: process "/bin/sh -c apt-get update && apt-get -y install --no-install-recommends     software-properties-common     libusb-1.0-0-dev     python3-colcon-common-extensions     python3-rosdep     build-essential     gpiod     libasound2-dev     ros-humble-cv-bridge     ros-humble-image-transport     ros-humble-image-transport-plugins     ros-humble-rmw-cyclonedds-cpp     gstreamer1.0-plugins-bad     alsa-utils     mpg123     libmpg123-dev     ros-humble-rtabmap-slam     unzip     ffmpeg     ros-humble-image-proc     git     htop     libsndfile1-dev     libsndfile1" did not complete successfully: exit code: 1