$1.$ Using the vi editor: Create a document with four lines, each containing the word $$today$.$ What command would you use to save the file, and exit vi$?2.$ Using the vi editor: Create a document called first.file, and enter a few lines of text in it$.$ Save it$.$ Create a second document called second.file, and enter a few lines of text in it$.$ Save it$.$ What commands would you use to create a third document called third.file by merging the text from the first two files? $(3$ pts$)$