README: Add executable documentation

Author: minad

.gitignore

@@ -4,5 +4,4 @@
 \#*\#
 /*-autoloads.el
 /*-pkg.el
-/gnuplot-*.*.*/
-/gpelcard.ps
+/gnuplot-*/

README.org

@@ -136,12 +136,23 @@ until this issue is fixed upstream.
 * Maintenance of generated files
 
 The files ~gnuplot.texi~ and ~gnuplot-eldoc.el~ are generated from the Gnuplot
-source. The source can be pulled downloaded from here:
-
-- https://packages.debian.org/unstable/gnuplot
-- http://deb.debian.org/debian/pool/main/g/gnuplot/gnuplot_6.0.2+dfsg1.orig.tar.xz
-
-1. Run ~emacs -batch -l doc2texi.el -f d2t-doc-to-texi~ inside the ~gnuplot-*/docs/~
-   source directory.
-2. Run ~makeinfo --no-split gnuplot.texi~ and ensure that it compiles cleanly.
-3. Copy ~gnuplot-eldoc.el~ and ~gnuplot.texi~ to the package source directory.
+source, which can be obtained from https://packages.debian.org/unstable/gnuplot.
+
+#+begin_src bash
+# Download and extract the Gnuplot source
+[ -e gnuplot-source.tar.xz ] || curl -o gnuplot-source.tar.xz http://deb.debian.org/debian/pool/main/g/gnuplot/gnuplot_6.0.2+dfsg1.orig.tar.xz
+rm -rf gnuplot-source/
+mkdir gnuplot-source
+tar --strip-components=1 -C gnuplot-source -xf gnuplot-source.tar.xz
+
+# Run doc2texi.el inside the gnuplot-source/docs directory
+cp doc2texi.el gnuplot-source/docs
+cd gnuplot-source/docs
+emacs -batch -l doc2texi.el -f d2t-doc-to-texi
+
+# Make sure that the info file compiles cleanly
+makeinfo --no-split gnuplot.texi
+
+# Copy the updated gnuplot-eldoc.el and gnuplot.texi to the package directory
+cp gnuplot.texi gnuplot-eldoc.el ../..
+#+end_src