Event for first time build in watch, serve mode

[njfamirm]

Is your feature request related to a problem? Please describe.

I'm wrote a simple plugin to load fonts from another npm package and copy to output

export function eleventyCopyFontPlugin(eleventyConfig: any, options: EleventyCopyFontPluginOptions): void {
  eleventyConfig.on('eleventy.before', async () => {
    await copyFont(options.fontName, options.outputDirectory);
  });
}

My issue is the eleventy.before event is run in each build, but my proccs must handle single time

Describe the solution you'd like

Simple eleventy.init or path through copy done event

Describe alternatives you've considered

No response

Additional context

No response