Allow text file editing

CHDataManagement/Model/FileResource.swift

@@ -98,6 +98,10 @@ final class FileResource: Item, LocalizedItem {
         content.storage.fileContent(for: id) ?? ""
     }
 
+    func save(textContent: String) -> Bool {
+        content.storage.save(fileContent: textContent, for: id)
+    }
+
     func dataContent() -> Foundation.Data? {
         content.storage.fileData(for: id)
     }