Rethink and write UTILS introductory definition for the user quick start guide

[tapaswenipathak]

In the user quick start guide I think our definition of UTILS is a bit outdated. By now, we include experimental, little tested tools there as well.

Ref #65 (comment).

[tapaswenipathak]

Besides TOPP, OpenMS offers a range of other tools. They are not included in TOPP as they are not part of typical analysis pipelines, but they still might be very helpful to you.
Just as the TOPP tools, they can be found in the OpenMS/bin folder.
The UTILS tools are divided into several subgroups:

I think is the only introductory definition and is very dependent.

https://abibuilder.informatik.uni-tuebingen.de/archive/openms/Documentation/nightly/html/UTILS_documentation.html

[jpfeuffer]

This one is already a bit better than the one in the docs but not perfect.