doc: update APL NUC GSG

APL NUC Getting started guide has some obsolete information (such as
saying the user had to build ACRN as part of the installation process
and changed instructions because the Clear Linux installer changed),
along with some spelling and grammar issues.

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

doc/getting-started/apl-nuc.rst

@@ -24,7 +24,7 @@ Connecting to the serial port
 If you don't need a serial console you can ignore this section. 
 
 Neither the APL or KBL NUCs present an external serial port interface.
-However, the KBL NUC does have a serail port header you can
+However, the KBL NUC does have a serial port header you can
 expose with a serial DB9 header cable. You can build this cable yourself,
 referring to the `KBL NUC product specification
 <https://www.intel.com/content/dam/support/us/en/documents/mini-pcs/nuc-kits/NUC7i7DN_TechProdSpec.pdf>`__
@@ -75,10 +75,10 @@ Software setup
 Set up a Clear Linux Operating System
 =====================================
 
-Currently, an installable version of ACRN does not exist. Therefore, you
+We begin by installing Clear Linux* as the development OS on the NUC.
-need to setup a base Clear Linux OS and you'll build and bootstrap ACRN
+The Clear Linux release includes an ``acrn.efi`` hypervisor application
-on your platform. You'll need a network connection for your platform to
+that will be added to the EFI partition (by the quick setup script or
-complete this setup.
+manually, as described below).
 
 .. note::
 
@@ -93,8 +93,8 @@ complete this setup.
    <https://clearlinux.org/documentation/clear-linux/get-started/bare-metal-install>`__
    as a starting point for installing Clear Linux OS onto your platform. Follow the recommended
    options for choosing an **Advanced options** installation type, and using the platform's
-   storage as the target device for installation (overwriting the existing data
+   storage as the target device for installation (overwriting the
-   and creating three partitions on the platform's storage drive).
+   existing data).
 
    When setting up Clear Linux on your NUC:
 
@@ -102,12 +102,13 @@ complete this setup.
    #.  With Clear Linux OS highlighted, select Enter.
    #.  From the Main Menu, select "Configure Media" and set
        "Auto Partition" to your desired hard disk.
-   #.  ``shift + A`` to the "Advanced options".
+   #.  Press :kbd:`A` to show the "Advanced options".
    #.  Select "Additional Bundle Selection" to add bundles for
        "desktop-autostart", "editors", "network-basic", "user-basic"
    #.  Select "User Manager" to add an administrative user "clear" and
        password.
    #.  Select "Assign Hostname" to set the hostname as "clr-sos-guest"
+   #.  Select Confirm to start installation.
 
 #. After installation is complete, boot into Clear Linux OS, login as
    **clear** (using the password you set earlier).
@@ -308,11 +309,13 @@ OS and started up a UOS VM.
 Manual setup ACRN guide
 =======================
 
-If you don't need the script to setup ACRN by manual, and then you should follow these steps
+Instead of using the quick setup script, you can also set up ACRN, SOS,
-after installation of Clear Linux and login system.
+and UOS manually following these steps:
 
+#. After installing Clear Linux on the NUC, login as the **clear** user
+   and open a terminal window.
 #. Clear Linux OS is set to automatically update itself. We recommend that you disable
-   this feature to have more control over when the updates happen. Use this command
+   this feature to have more control over when updates happen. Use this command
    to disable the autoupdate feature:
 
    .. code-block:: none
@@ -346,7 +349,7 @@ after installation of Clear Linux and login system.
       +--------------------+---------------------------------------------------+
       | Bundle             | Description                                       |
       +====================+===================================================+
-      | service-os         | Add the acrn hypervisor, the acrn devicemodel and |
+      | service-os         | Add the acrn hypervisor, acrn devicemodel, and    |
       |                    | Service OS kernel                                 |
       +--------------------+---------------------------------------------------+
       | kernel-iot-lts2018 | Run the Intel kernel "kernel-iot-lts2018"         |
@@ -374,7 +377,7 @@ partition. Follow these steps:
       loaderx64.efi
 
    .. note::
-      On Clear Linux OS, the EFI System Partion (e.g.: ``/dev/sda1``)
+      On Clear Linux OS, the EFI System Partition (e.g.: ``/dev/sda1``)
       is mounted under ``/boot`` by default
       The Clear Linux project releases updates often, sometimes
       twice a day, so make note of the specific kernel versions