Create cs_city_dump_small.json

[mx-moonling]

Summary

Content "Makes most furniture in the small dump be placed randomly when the map square is generated, as well as adding freezers to the pool (useful new appliance)."

Purpose of change

Freezers are currently only available in ice-cream stores. This change makes freezers somewhat easier to find, and also makes each dump more unique, without changing the core structure. It also now is easier to add other furniture to the pool that can spawn, for use in mods or when adding new appliances.

Describe the solution

This modifies the small dump mapgen to generate random furniture from a weighted list on tiles marked as an asterisk.

Describe alternatives you've considered

Building a static dump mapgen that includes freezers and does not otherwise change the layout.
Making a more complex series of weights for the various furnitures that can spawn.

Testing

Created new world with minimal mods, found a city, observed the new contents of the dump.

Additional context

[Night-Pryanik]

Please run linter through your changes, for example via http://dev.narc.ro/cataclysm/format.html.