Getting Started: Tweak the content for beginners

[ianp5a]

"Getting started. What is Markdown?" is a great, useful section that has been carefully written for people completely new to markdown. However the focus is on the "Format, and not the File". I suggest a small tweak for clarity.

Explanation:
Some places require a markdown file. And, sensibly, refer newbies to the Markdown Guide. Many people know MS Word and MS Word files, and typically assume that Markdown files need the Markdown application. They have never seen or know the existence of plain text files.

My suggestion:
Explain that a special Markdown application is not required. And explain briefly what a plain text file is.

Paragraph 4 Before:
You can add Markdown formatting elements to a plaintext file using a text editor application. Or you can use one of the many Markdown applications for macOS, Windows, Linux, iOS, and Android operating systems.
Paragraph 4 After (suggestion):
Markdown text is stored in a normal text file. The sort of file created with any text editor application such as Notepad. And can have any file name extension such as .txt or .md. The file contains only plain text, including the Markdown formatting elements. You can use one of the many Markdown applications for macOS, Windows, Linux, iOS, and Android operating systems. But no dedicated application is needed.

(But maybe there way to express it better than my suggestion.)