Write down recommendations of folder naming

[jhnns]

ESLint doesn't have good rules to enforce specific folder or file naming conventions (there are plugins for this, but they're not really good).

Here are my thoughts on this topic:

• In general, there are no "mandatory" rules for files and folder names. Each convention is fine as long as it is consistent throughout the project.
• Most of the time we use camelCase:
  • starting with a lowercase letter for regular modules
  • starting with an uppercase letter (aka PascalCase) for things that can have instances (classes or components)
• Should folder names be plural or singular? I think, this is a good answer. Use plural if the directory name describes their "type", use singular if it describes something beyond their type. This is a perfect example: pictures/Jacobs Birthday pictures is the type, Jacobs Birthday groups the pictures in a different way.

We should write down a list with recommendations.