Migrating the troubleshooting guide from SAAS repo
+ adding a paragraph about issues with embedding iframes related to HTTP headers and cookie parameters.
Scripts in module mode need to be abide by the Same Origin Policy (CORS headers are used to load them)
This can cause issues on some setups.
This commit adds a new "scriptDisableModuleSupport" that can be used to disable the "modules" mode.
Closes#1721
Because the workadventu.re website documentation regarding map building directly comes from that repo, it makes sense to export the menu in the repo.
This way, when we add a new documentation page, we can edit the menu in the same pull request.