French translation

[tbolon]

This is a follow-up from #24

I have updated my template to use the integrated system and rebased to the current master branch.

I receive an error each time I try to run the build command:

## Creating first time compiled artifacts for template ./dist/template.fr/template-versafix-1.fr.html
Exception while compiling template: ./dist/template.fr/template-versafix-1.fr.html TypeError [ERR_INVALID_ARG_TYPE]: The "data" argument must be of type string or an instance of Buffer, TypedArray, or DataView. Received undefined
    at Object.writeFileSync (node:fs:2354:5)
    at checkTemplateDefs (D:\code\github\versafix-template\src\checkTemplateDefs.js:100:8)
    at Object.<anonymous> (D:\code\github\versafix-template\src\index.js:55:7)
    at Module._compile (node:internal/modules/cjs/loader:1358:14)
    at Module._extensions..js (node:internal/modules/cjs/loader:1416:10)
    at Module.load (node:internal/modules/cjs/loader:1208:32)
    at Module._load (node:internal/modules/cjs/loader:1024:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:174:12)
    at node:internal/main/run_main_module:28:49 {
  code: 'ERR_INVALID_ARG_TYPE'
}
WARNING: loading non-allowed module: async

I can't find what is the cause of this (no warning for the other templates). I paid attention to escaping the ' character when used but can't find what could cause this message.
The assets seems to be generated correctly, and I am able to use the template in mosaico.

I suggest you try to run the build from this PR on your device to find the cause of this error.

Thanks 🙏