[devdocsgjs/main: 1007/1867] Add docs for using the Gnuplot scraper

[Andy Holmes <andyholmes src gnome org>]

commit 3e04069b69f411e001da63016b33f18bb114b3ba
Author: Jed Fox <git twopointzero us>
Date:   Mon Jan 13 12:15:00 2020 -0500

    Add docs for using the Gnuplot scraper

 docs/file-scrapers.md | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
---
diff --git a/docs/file-scrapers.md b/docs/file-scrapers.md
index 912517d1..bf047688 100644
--- a/docs/file-scrapers.md
+++ b/docs/file-scrapers.md
@@ -34,6 +34,26 @@ Go to https://www.erlang.org/downloads and download the HTML documentation file.
 ### GCC
 ### GNU Fortran
 
+## Gnuplot
+
+NOTE: these steps may not work on macOS.
+
+Find the most recent tagged version on https://sourceforge.net/p/gnuplot/gnuplot-main/ref/master/tags/
+and change `1.2.3` below to that tag when running the clone.
+
+```sh
+DEVDOCS_ROOT=/path/to/devdocs
+mkdir gnuplot-src gnuplot-conf $DEVDOCS_ROOT/docs/gnuplot
+git clone -b $RELEASE --depth 1 https://git.code.sf.net/p/gnuplot/gnuplot-main ./gnuplot-src
+cd gnuplot-src/
+./prepare
+cd ../gnuplot-conf
+../gnuplot-src/configure
+cd docs/
+make nofigures.tex
+latex2html -html 5.0,math -split 4 -link 8 -long_titles 5 -dir $DEVDOCS_ROOT/docs/gnuplot -ascii_mode 
-no_auto_link nofigures.tex
+```
+
 ## NumPy
 
 ## OpenJDK