Create a file `append-output.sh` that will get the output of a file and parse it, and then write it to a file with a specific format using a single command.
Get the content of the file `songs.txt`, parse it with the `grep` command to filter the file in order to get all the songs from the artist whose names start with `J`, and write the output to the existing file `results.txt`, check the example below:
Here, `command1` is the command that generates the output you want to parse, and `command2` is the command that parses the output. The output of `command2` will be redirected to the file `output_file` using the `>>` operator. If the file `output_file` already has some content inside, the file operator `>>` command will append to that file, unlike the `>` which will delete the content inside.
