chore(docs): Fix missing quotation mark (#21529)

docs/tutorial/part-zero/index.md

@@ -12,7 +12,7 @@ The command line is a text-based interface used to run commands on your computer
 
 Take a moment to locate and open up the command line interface (CLI) for your computer. Depending on which operating system you are using, see [**instructions for Mac**](http://www.macworld.co.uk/feature/mac-software/how-use-terminal-on-mac-3608274/), [**instructions for Windows**](https://www.lifewire.com/how-to-open-command-prompt-2618089) or [**instructions for Linux**](https://www.howtogeek.com/140679/beginner-geek-how-to-start-using-the-linux-terminal/).
 
-_Note: If you’re new to the command line, "running" a command, means writing a given set of instructions in your command prompt, and hitting the Enter key”. Commands will be shown in a highlighted box, something like `node --version`, but not every highlighted box is a command! If something is a command it will be mentioned as something you have to run/execute._
+_Note: If you’re new to the command line, "running" a command, means "writing a given set of instructions in your command prompt, and hitting the Enter key". Commands will be shown in a highlighted box, something like `node --version`, but not every highlighted box is a command! If something is a command it will be mentioned as something you have to run/execute._
 
 ## Install Node.js for your appropriate operating system