Maaspower provides a schema for its configuration file. If you use a schema aware YAML editor then this will use hints and auto completion to help create the config.
You can generate a schema file with the command:
masspower schema <schema file name>
You can instruct schema aware editors to use a schema file with the following modeline at the start of the YAML file:
# yaml-language-server: $schema=https://my.url.to/the/schema
Note that local schema files are supported with relative or absolute file names (at least in vscode).
A popular choice for YAML aware editing is vscode.
Below is a useful discussion on yaml/json schema including how to enable schema validated editing of yaml files in vscode.