This directory contains configuration files needed for Besti to run properly. 

startup.horse is the configuration file for the texture database maker. If you want to rebuild the texture database, look for the lines:

<key>GeneratePonyTextureDatabase</key>
<value xsi:type="xsd:boolean">false</value>

If you set that to "true" instead of "false", the system will rebuild the texture database out of the source Jpeg images the next time you start Besti. It will set itself back to false again after it finishes this process.