manual: limit width to 45em

I had a local user stylesheet that was doing this for all sites
so I hadn't noticed how bad it was!

diff --git a/configure.py b/configure.py
index 79d6ac9..c35cf6f 100755 (executable)
--- a/configure.py
+++ b/configure.py
@@ -319,7 +319,7 @@ n.newline()
 
 n.comment('Generate the manual using asciidoc.')
 n.rule('asciidoc',
-       command='asciidoc -a toc -o $out $in',
+       command='asciidoc -a toc -a max-width=45em -o $out $in',
        description='ASCIIDOC $in')
 manual = n.build(doc('manual.html'), 'asciidoc', doc('manual.asciidoc'))
 n.build('manual', 'phony',