Add documentation on short-names

Once we settle on the wording for short-names in podman-pull, I will
add the same section to all of the podman commands that use pull.

Also ran through all man pages with a spell checker.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

docs/tutorials/mac_client.md

@@ -1,2 +1,2 @@
 # [Podman Mac Client tutorial](https://github.com/containers/podman/blob/master/docs/tutorials/mac_win_client.md)
-This tutorial has moved! You can find out how to set up Podman on MacOS (as well as Windows) [here](https://github.com/containers/podman/blob/master/docs/tutorials/mac_win_client.md)
+This tutorial has moved! You can find out how to set up Podman on macOS (as well as Windows) [here](https://github.com/containers/podman/blob/master/docs/tutorials/mac_win_client.md)

docs/tutorials/mac_win_client.md

@@ -1,4 +1,4 @@
-# Podman Remote clients for MacOS and Windows
+# Podman Remote clients for macOS and Windows
 
 ## Introduction
 
@@ -18,7 +18,7 @@ Once you have downloaded the installer, simply double click the installer and Po
 
 Podman must be run at a command prompt using the Windows ‘cmd” or powershell applications.
 
-### MacOS
+### macOS
 
 The Mac Client is available through [Homebrew](https://brew.sh/). You can download homebrew via the instructions on their site. Install podman using:
 ```

docs/tutorials/podman-go-bindings.md

@@ -536,7 +536,7 @@ containers and pods in a way which fits very nicely in many production environme
 
 
 ## References
-- Podman is available for most major distributions along with MacOS and Windows.
+- Podman is available for most major distributions along with macOS and Windows.
 Installation details are available on the [Podman official website](https://podman.io/getting-started/).
 
 - Documentation can be found at the [Podman Docs page](https://docs.podman.io).