doc: GSG apt install command DX improvement

As recommended, add a ``-y`` to the ``apt install`` commands so they
don't prompt the user to confirm the installation, seen as unnecessary
in this context.

Also, wrap lines that are longer then 80 chars to improve git reviews
and follow our doc conventions.

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>

doc/getting-started/getting-started.rst

@@ -47,10 +47,11 @@ Before you begin, make sure your machines have the following prerequisites:
 * Hardware specifications
 
   - Target board (see :ref:`hardware_tested`)
-  - Ubuntu 18.04 Desktop bootable USB disk: download the `Ubuntu 18.04.05 Desktop
+  - Ubuntu 18.04 Desktop bootable USB disk: download the `Ubuntu 18.04.05
-    ISO image <https://releases.ubuntu.com/18.04.5/>`_ and follow the `Ubuntu documentation
+    Desktop ISO image <https://releases.ubuntu.com/18.04.5/>`_ and follow the
+    `Ubuntu documentation
     <https://ubuntu.com/tutorials/create-a-usb-stick-on-ubuntu#1-overview>`__
-    for instructions for creating the USB disk.
+    for creating the USB disk.
   - USB keyboard and mouse
   - Monitor
   - Ethernet cable and Internet access
@@ -72,7 +73,8 @@ To set up the hardware environment:
 #. Connect the target system to the LAN with the Ethernet cable.
 
 #. (Optional) Connect the serial cable between the target and development
-   computer to view the ACRN and VM console (for an example, see :ref:`connect_serial_port`).
+   computer to view the ACRN and VM console (for an example, see
+   :ref:`connect_serial_port`).
 
 Example of a target system with cables connected:
 
@@ -113,7 +115,7 @@ To set up the ACRN build environment on the development computer:
 
    .. code-block:: bash
 
-      sudo apt install gcc \
+      sudo apt install -y gcc \
            git \
            make \
            vim \
@@ -157,8 +159,9 @@ To set up the ACRN build environment on the development computer:
       make clean && make iasl
       sudo cp ./generate/unix/bin/iasl /usr/sbin
 
-#. Get the ACRN hypervisor and kernel source code.  (Note these checkout tags
+#. Get the ACRN hypervisor and kernel source code. (Because the acrn-kernel repo
-   will be updated when we launch the v2.6 release):
+   has a lot of Linux kernel history, you can clone the relevant release branch
+   with minimal history, as shown here.)
 
    .. code-block:: bash
 
@@ -168,9 +171,7 @@ To set up the ACRN build environment on the development computer:
       git checkout v2.6
 
       cd ..
-      git clone https://github.com/projectacrn/acrn-kernel
+      git clone --depth 1 --branch release_2.6 https://github.com/projectacrn/acrn-kernel
-      cd acrn-kernel
-      git checkout release_2.6
 
 .. _gsg-board-setup:
 
@@ -179,9 +180,10 @@ To set up the ACRN build environment on the development computer:
 Prepare the Target and Generate a Board Configuration File
 ***************************************************************
 
-A **board configuration file** is an XML file that stores hardware-specific information extracted from the target system. The file is used to configure
+A **board configuration file** is an XML file that stores hardware-specific
-the ACRN hypervisor, because each hypervisor instance is specific to your
+information extracted from the target system. The file is used to configure the
-target hardware.
+ACRN hypervisor, because each hypervisor instance is specific to your target
+hardware.
 
 You use the **board inspector tool** to generate the board
 configuration file.
@@ -265,7 +267,7 @@ Generate a Board Configuration File
 
    .. code-block:: bash
 
-      sudo apt install cpuid msr-tools pciutils dmidecode python3 python3-pip
+      sudo apt install -y cpuid msr-tools pciutils dmidecode python3 python3-pip
 
 #. Install the Python package dependencies:
 
@@ -391,7 +393,8 @@ Generate a Board Configuration File
 Generate a Scenario Configuration File and Launch Script
 *********************************************************
 
-You use the **ACRN configurator** to generate scenario configuration files and launch scripts.
+You use the **ACRN configurator** to generate scenario configuration files and
+launch scripts.
 
 A **scenario configuration file** is an XML file that holds the parameters of
 a specific ACRN configuration, such as the number of VMs that can be run,
@@ -434,7 +437,8 @@ To generate a scenario configuration file and launch script:
       .. image:: ./images/gsg_config_scenario_default.png
          :class: drop-shadow
 
-   #. In the dialog box, select **industry** as the default scenario setting and click **OK**.
+   #. In the dialog box, select **industry** as the default scenario setting and
+      then click **OK**.
 
       .. image:: ./images/gsg_config_scenario_load.png
          :class: drop-shadow
@@ -457,7 +461,8 @@ To generate a scenario configuration file and launch script:
       .. image:: ./images/gsg_config_scenario_save.png
          :class: drop-shadow
 
-   #. Confirm that ``industry.xml`` appears in the directory ``/home/<username>/acrn-work``.
+   #. Confirm that ``industry.xml`` appears in the directory
+      ``/home/<username>/acrn-work``.
 
 #. Generate the launch script:
 
@@ -574,7 +579,8 @@ Install ACRN
 
 In the following steps, you will configure GRUB on the target system.
 
-#. On the target, find the root file system (rootfs) device name by using the ``lsblk`` command:
+#. On the target, find the root file system (rootfs) device name by using the
+   ``lsblk`` command:
 
    .. code-block:: console
       :emphasize-lines: 24
@@ -608,7 +614,8 @@ In the following steps, you will configure GRUB on the target system.
    partition named ``/``, in this case ``nvme0n1p2``.
 
 #. Run the ``blkid`` command to get the UUID and PARTUUID for the rootfs device
-   (replace the ``nvme0n1p2`` name with the name shown for the rootfs on your system):
+   (replace the ``nvme0n1p2`` name with the name shown for the rootfs on your
+   system):
 
    .. code-block:: bash
 
@@ -755,10 +762,10 @@ Launch the User VM
 
       vi ~/acrn-work/launch_uos_id3.sh
 
-#. Look for the line that contains the term ``virtio-blk`` and replace
+#. Look for the line that contains the term ``virtio-blk`` and replace the
-   the existing image file path with your ISO image file path.
+   existing image file path with your ISO image file path.  In the following
-   In the following example, the
+   example, the ISO image file path is
-   ISO image file path is ``/home/acrn/acrn-work/ubuntu-18.04.5-desktop-amd64.iso``.
+   ``/home/acrn/acrn-work/ubuntu-18.04.5-desktop-amd64.iso``.
 
    .. code-block:: bash
       :emphasize-lines: 4
@@ -828,4 +835,5 @@ The User VM has launched successfully. You have completed this ACRN setup.
 Next Steps
 **************
 
-:ref:`overview_dev` describes the ACRN configuration process, with links to additional details.
+:ref:`overview_dev` describes the ACRN configuration process, with links to
+additional details.