Move cities.md Files out of the 'City' Folders into their proper locations

[SpocWeb]

Cities were automatically moved to the closest matching area,
but they should be placed 'above' Folders with the same Name, describing the same Object.
This implements the 'Folder Note'-Pattern to add Metadata to a Folder
by adding a File of the same Name to the Parent Folder.
This requires to check for Spelling Errors and Plausibility.