How to read and write files in Go: a complete guide for beginners

Hello everyone! I just started learning Go and ran into a problem: I can't understand how to work with files properly. I need to write a simple program that reads data from one text file, processes it, and writes the result to another file.\n\nI tried several approaches, but I keep running into errors. Here's what I tried to do:\n\n```go\npackage main\n\nimport "fmt"\n\nfunc main() {\n // Trying to read a file\n data := readFile("input.txt")\n // Process the data\n result := processData(data)\n // Write the result\n writeFile("output.txt", result)\n}\n\nfunc readFile(filename string) string {\n // Here I don't know what to write\n return ""\n}\n\nfunc processData(data string) string {\n return "Processed: " + data\n}\n\nfunc writeFile(