add manpage for help command

Signed-off-by: Tomas Tomecek <ttomecek@redhat.com>

Closes: #941
Approved by: rhatdan

docs/atomic-help.1.md

@@ -0,0 +1,27 @@
+% ATOMIC(1) Atomic Man Pages
+% Tomas Tomecek
+% May 2017
+# NAME
+atomic-help - Get help for container images
+
+# SYNOPSIS
+**atomic help**
+[**-h**|**--help**]
+IMAGE
+
+**atomic help** provides documentation for the specified container IMAGE.
+
+The documentation is extracted from the container image. **atomic** searches
+for the documentation in following locations:
+
+1. File placed inside root of the container named either **help.1** or
+**README.md**.
+2. Label named **help** which should contain executable command
+to display the documentation.
+
+# OPTIONS
+**-h** **-help**
+  Print usage statement.
+
+# HISTORY
+May 2017, Originally compiled by Tomas Tomecek (ttomecek at redhat dot com)