Prerequisites

An ASI Loader (Ultimate ASI Loader is recommended)
GTA: San Andreas v1.0 US (Other versions are not supported)
Installation

Download the Rainbomizer archive from GitHub Releases (check the Downloads section)
Extract the ASI file (optionally the config file) into the scripts folder or the root directory of your San Andreas Installation.
Configuration

rainbomizer/config.toml contains the configuration options for Rainbomizer.
It will be automatically created by the ASI File upon launching the game. Alternatively, you can find the default config file in the archive.
The config file uses the TOML format and can be opened in any text editor (like Notepad). It is similar in structure to INI files.
To enable/disable a certain Randomizer, you have to locate its section in the config file, and change the Enabled key to true/false to enable/disable it.
Documentation for additional configration options for individual randomizers can be found in the default config file.