I prefer the **Markdown** plugin for additional formatting. It is the sixth choice in the first column of the factory list of plugins.
Click the [+] symbol at the bottom of the wiki page. This creates a gray "factory" at the end of the story.
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There are at least three text editors available. One is a text editor plug in, another is an HTML plugin, and the third is a markdown plugin.
Text: Double-click the gray to open the simple text editor. Proceed as you would to Add Text to existing paragraphs.
Ward Cunningham prefers this simple text editor.
I suppose that if you know HTML markup you might prefer HTML. The reader of your paragraphs cannot tell which you have used unless they double click on the paragraph and then click Control-I for "information".