price estimator - explanations for machine subscription types

[matuskosut]

add explanation for Commitment / On-demand / Spot

very brief example:

<autocomplete>
  <item>
     <title>Commitment</title>
     <subtitle>Explanation....</subtitle>
  </item>
  ....
...

[matuskosut]

Draft:

Commitment
Commitment subscription is for required lab machines.

On-demand
On-demand machines are additional machine for long term usage.

Spot
For cheaper, short-term intensive computation. Removed after 30 days.