Looks like you are wanting to mod Resonite and extend some of the capabilities or makes a few tweaks before they are implemented officially. A few quick bits to note before you jump in:

• Is modding allowed?: Yes, so long as Resonite's Policy's and Guidelines[resonite.com] are followed. However don't expect to get support from the team while using mods, instead ask in the Modding Discord[discord.gg].
  
• Will people know I'm using mods?: By default no, ResoniteModLoader attempts to remain non-detectable by itself, however some mods may make changes that have visible effects that others will be able to see.
  
• I have an issue I want to report: If an issue occurs while using mods, please do not report it on the Resonite Issue tracker. Instead post in the Modding Discord[discord.gg] (#help-and-support) and verify if it is an issue with a mod in the first place. If it occurs without using mods then report it on the Resonite Issue Tracker[github.com].

The full guide and additional details can be found on the ResoniteModLoader Github[github.com]

1. Download ResoniteModLoader[github.com] to Resonite's Libraries folder (C:\Program Files (x86)\Steam\steamapps\common\Resonite\Libraries). You may need to create this folder if it's missing.

2. Place 0Harmony[github.com] into a rml_libs folder under your Resonite install directory (C:\Program Files (x86)\Steam\steamapps\common\Resonite\rml_libs). You will need to create this folder.

3. Add the following to Resonite's launch options[github.com]: -LoadAssembly Libraries/ResoniteModLoader.dll. If you put ResoniteModLoader.dll somewhere else you will need to change the path.

4. Optionally add mod DLL files to a rml_mods folder under your Resonite install directory (C:\Program Files (x86)\Steam\steamapps\common\Resonite\rml_mods). You can create the folder if it's missing, or launch Resonite once with ResoniteModLoader installed and it will be created automatically.

5. Start the game. If you want to verify that ResoniteModLoader is working you can check the Resonite logs. (C:\Program Files (x86)\Steam\steamapps\common\Resonite\Logs). The modloader adds some very obvious logs on startup, and if they're missing something has gone wrong. Here is an example log[github.com] file where everything worked correctly.

For an easy way to find and manage mods, check out Resolute[github.com]. It simplifies the installation and updating for verified mods from the Mod Manifest[github.com].

New mods and updates also are posted in the Resonite Modding Discord[discord.gg].

If you experience trouble setting up mods or experience an issue with a mod, you can check out the Troubleshooting documentation[github.com] and/or create a post in the #help-and-support channel in discord, including details as to what is happening and what you have tried so far. Do note: we will likely ask you for your game logs to help diagnose issues, posting logs along side the initial issue will help resolve issues faster. The logs for your game will be where the game is installed in a /Logs/ folder.