All a file dedicated to configuration does it separate configurable settings from non-configurable/relevant code. The fact that the file is named config.lua or configuration.lua makes it no different than core.lua or MyAddon.lua or modules.lua etc.
Config1.lua:
Lua Code:
local _, AddonTable = ...
AddonTable.Config1 = {
MyNeatSetting = true,
MyNotSoNeatSetting = false
}
Config2.lua
Lua Code:
local _, AddonTable = ...
AddonTable.Config2 = {
DucksAreNeat = true,
CowsAreNeat = false
}
Understand that you can place anything you can place into a table, into the addon table. As such, you could split your configuration into 1000 files if you wanted to.