This PR marks some code blocks as examples that incorrectly weren't marked that way. It also marks some example tags as .output instead; this is an idea from #1161 that I thought made marking code blocks easier. All of the marks were cross-referenced with the printed book. I think of this both as superseding #1161 and also as preparation for trying to make the style of the online book look more like the printed book.
This PR marks some code blocks as examples that incorrectly weren't marked that way. It also marks some example tags as
.output
instead; this is an idea from #1161 that I thought made marking code blocks easier. All of the marks were cross-referenced with the printed book. I think of this both as superseding #1161 and also as preparation for trying to make the style of the online book look more like the printed book.