Add "How to Use it" section

or *AUR* [#]_ version.

It can be used by Dev and TUs to check if new release of their package are available.

HOW TO USE IT

=============

The first thing to do is to define a list of package to track by creating a file

~/.config/archversion.conf. This file look like an old fashioned INI file.

EXAMPLES

========

*archversion -d* will only display version which differ with cache.

*archversion -n* will only display new verions.

*archversion -nd* will display new version not in cache (useful for mail report).

You can find a nice example of this file in misc directory.

Then you can run:

*archversion check -d* to only display version which differ with cache.

*archversion check -n* to only display new verions.

*archversion check -nd* to display new versions not in cache.

Of course you can add the last one in a cron job to get a daily report of which

packages need updates.

COMPARING MODES

===============

*archversion* allow you to compare version against differents things, not only

official Archlinux repository.

You can compare upstream version against:

- An Archlinux package

- An AUR package

- A stored value

DEPENDENCIES