Improve CLI usage docs (#559)

* Remove example, improve structure, fix typo

docs/usage.rst

@@ -11,37 +11,23 @@ Ansible Builder can execute two separate steps. The first step is to create a bu
 The ``build`` command
 ---------------------
 
-The ``ansible-builder build`` command takes an execution environment definition file as an input. It outputs a build instruction file (Containerfile for Podman, Dockerfile for Docker), creates the build context necessary for building an execution environment image, and builds that image. The image can be re-built with the build context elsewhere, and give the same result. By default, it looks for a file named ``execution-environment.yml`` in the current directory.
+The ``ansible-builder build`` command:
 
-This example uses the following ``execution-environment.yml``
-file as a starting point:
+* takes an :ref:`execution environment definition file<builder_ee_definition>` as an input,
+* outputs a build instruction file (Containerfile for Podman, Dockerfile for Docker),
+* creates a build context necessary for building an execution environment image,
+* builds the image.
 
-.. code:: yaml
-
-    ---
-    version: 3
-    dependencies:
-      galaxy: requirements.yml
-
-
-The content of ``requirements.yml``:
-
-.. code:: yaml
-
-   ---
-   collections:
-     - name: awx.awx
+By default, it looks for a file named ``execution-environment.yml`` in the current directory.
 
-To build an execution environment using the files above, run:
+To build an execution environment using the default definition file, run:
 
 .. code::
 
    $ ansible-builder build
-   ...
-   STEP 7: COMMIT my-awx-ee
-   --> 09c930f5f6a
-   09c930f5f6ac329b7ddb321b144a029dbbfcc83bdfc77103968b7f6cdfc7bea2
-   Complete! The build context can be found at: context
+   Running command:
+     podman build -f context/Containerfile -t ansible-execution-env:latest context
+   Complete! The build context can be found at: /path/to/context
 
 Ansible Builder produces a ready-to-use container image and preserves the build context, which you can use to rebuild the image at a different time and/or location with the tooling of your choice.
 
@@ -219,7 +205,7 @@ Controls the final image layer squashing. Valid values are:
 
 .. note::
 
-   This flag is compatible only with the ``podman`` runtime and will be ignored for any other runtime. Docker does not suport layer squashing; it is considered an experimental feature.
+   This flag is compatible only with the ``podman`` runtime and will be ignored for any other runtime. Docker does not support layer squashing; it is considered an experimental feature.
 
 
 The ``create`` command