v5.1.13

Add config validation, performance improvements, doc improvements

• Validate the config file when the plugin loads, print a warning if any invalid item short names or invalid furnace entity short names, suggest the corresponding furnace entity short name when supplying a furnace item short name
• Improve performance when loading and unloading the plugin (replace expensive Unity FindObjectsOfType call)
• Reduce garbage allocations when canceling hooks OnOvenStart and OnOvenToggle
• Document what a fork means because people ask about this
• Document the configuration validation feature
• Document all current furnace entity short names