[Files Refactor] Import export fixup (#2763)

* Adjust json schema
* Remove mappings file from export
* Import file/folder support
* Update documentation
* Make gallery filenames unique

pkg/models/jsonschema/studio.go

@@ -23,6 +23,10 @@ type Studio struct {
 	IgnoreAutoTag bool             `json:"ignore_auto_tag,omitempty"`
 }
 
+func (s Studio) Filename() string {
+	return s.Name + ".json"
+}
+
 func LoadStudioFile(filePath string) (*Studio, error) {
 	var studio Studio
 	file, err := os.Open(filePath)