mod_skel provides a template for new modules. It has the basic components to allow a new module to be written, with no code that does anything useful beyond loading the module into FreeSWITCH
mod_skel is part of the FreeSWITCH source tree. To get it just clone FreeSWITCH as normal.
Direct link to mod_skel: https://github.com/signalwire/freeswitch/tree/master/src/mod/applications/mod%5Fskel