update getting started

Author: olegantonyan

docs/getting_started.md

@@ -1,14 +1,15 @@
-# Installing omnipackage-agent
+# Getting started
 
-Agent is responsible for building packages. You'll need it to build packages locally.
+## Installing omnipackage-agent
 
-## Multiple ways to install it
+Agent is responsible for building packages. You'll need it to build packages locally. There are multiple ways to install it:
 
-1. OmniPackage repositories [web.omnipackage.org/oleg/omnipackage-agent](https://web.omnipackage.org/oleg/omnipackage-agent).
-2. [Source code](https://github.com/omnipackage/omnipackage-agent-ruby). Reasonable recent version of Ruby is required, as well as docker or podman. Executables located in `exe/` directory.
-
-## Test your installation
+1. OmniPackage repositories [web.omnipackage.org/oleg/omnipackage-agent](https://web.omnipackage.org/oleg/omnipackage-agent)
+2. [Source code](https://github.com/omnipackage/omnipackage-agent-ruby). Reasonably recent version of Ruby required. Executables located in `exe/` directory
 
+Test your installation
 ```shell
-omnipackage --version
+omnipackage --check
 ```
+
+Agent requires `podman` or `docker` as well as few other common Linux programs. It will check their availability upon start and report if anything is missing.