subplot.md: Add example of noNumberLines

Signed-off-by: Daniel Silverstone <dsilvers@digital-scurf.org>

1 files changed, 35 insertions, 0 deletions

diff --git a/subplot.md b/subplot.md
index f2cd6c1..65f9830 100644
--- a/subplot.md
+++ b/subplot.md
@@ -388,6 +388,41 @@ Subplot also understands the `dot` and `roadmap` tags, and can use the
 Graphviz dot program, or the [roadmap][] Rust crate, to produce
 graphs. These can useful for describing things visually.
 
+When typesetting files, Subplot will automatically number the lines in
+the file so that documentation prose can refer to sections of embedded
+files without needing convoluted expressions of positions.  However if
+you do not want that, you can annotate the file with `.noNumberLines`.
+
+For example…
+
+~~~~~~~~markdown
+~~~{#numbered-lines.txt .file}
+This file has numbered lines.
+
+This is line number three.
+~~~
+
+~~~{#not-numbered-lines.txt .file .noNumberLines}
+This file does not have numbered lines.
+
+This is still line number three, but would it be obvious?
+~~~
+~~~~~~~~
+
+…renders as:
+
+~~~{#numbered-lines.txt .file}
+This file has numbered lines.
+
+This is line number three.
+~~~
+
+~~~{#not-numbered-lines.txt .file .noNumberLines}
+This file does not have numbered lines.
+
+This is still line number three, but would it be obvious?
+~~~
+
 [roadmap]: https://crates.io/search?q=roadmap