How to Symlink
Symlinking allows you to set a file or folder in multiple locations. This can be a useful tool in modpack development for when you want to keep 1 set of mod files and not have to copy and paste. For example, downloading and updating mods using GDLauncher or the Curseforge app is extremely simple. However, if you want to use the advanced tools of MultiMC to launch and dev your pack you can’t set their folders to be the same. They have a different folder structure. Instead, you can symlink or ‘clone’ the original mod folder into a MultiMC instance and it will exist in both locations at the same time. You can then use GD or Curseforge to update your mods and launch from MultiMC.
Since you will need to export the modpack to post to Curseforge, you will have to symlink to config and script folders to the Curseforge location.