Title says it all: How to make a Report Folder publicly accessible for everyone in the org?
If by 'everyone in the org' you mean all internal users, then there's already a public group you can share the report folder with to do this.
Following the help doc, you can go to
Reports --> All Folders
Right click on the down arrow at the right side of the folder and select
Now, on the sharing screen, you can select Public Groups to share with. Search for
All Internal Users and it should eventually display (might take a second). Select that group and set the
Access to view.
Now, all internal users have view access to that folder.