Use txt2tags to format intro text.

That way we can include basic markup in the into text and use it in
both LaTeX and HTML.

Take advantage of this to expand the wording of the intro text in all
books.

Library/intro.txt

@@ -1 +1,8 @@
-This book is for tunes that may not be part of the regular Havoc session or dance repertoire, but which I want to try over.
+This is a txt2tags input file.
+The first 3 lines are headers, and are ignored.
+
+This book is for tunes that are not part of the regular
+Havoc session or dance repertoire.
+
+Typically these tunes have either fallen out of popularity at sessions,
+or are simply tunes that I like.

Morris/intro.txt

@@ -1 +1,7 @@
-This book provides the dots for all dance tunes commonly performed by Cry Havoc.
+This is a txt2tags input file.
+The first 3 lines are headers, and are ignored.
+
+This book provides the dots for the music to all the dances
+performed by Cry Havoc. The name of the dance is given as the tune title.
+If the name of the tune differs from the name of the dance, the tune
+name is given in the subtitle.

Session/intro.txt

@@ -1 +1,13 @@
-This book provides the dots for all tunes commonly played at Cry Havoc music sessions.
+This is a txt2tags input file.
+The first 3 lines are headers, and are ignored.
+
+This book provides the dots for the tunes commonly played at Cry Havoc
+music sessions.
+
+The set of tunes played at sessions does tend to vary over time. Some
+tunes are perennial favourites and so are included here automatically.
+Others are less regular, and so their inclusion is to some extent a
+personal choice. I aim to only include tunes that I remember hearing at
+a session in the not too distant past, but nobody keeps a detailed log
+of what gets played, so the choice is imprecise. And may well be influenced
+by personal preference.

dottes.tex

@@ -181,7 +181,7 @@ Havoc musicians come in all shades of experience and ability.
 This collection is intended to help those like me who are inexpert with
 instrument and folk music generally, but have a little musical background.
 
-\input{intro.txt}
+\input{intro.tex}
 
 Being folk tunes, many of the tunes herein have many variations.
 The music presented here is my attempt at reflecting what the musicians

makeBooke.sh

@@ -25,7 +25,7 @@ mkdir -p $builddir
 cp dottes.tex $builddir
 cp buildno.txt $builddir
 cp buzzard.pdf $builddir
-for item in title subtitle intro instrument
+for item in title subtitle instrument
 do
     rm -f $builddir/$item.txt
     if [ -r $booke/$item.txt ]; then
@@ -34,6 +34,15 @@ do
         touch $builddir/$item.txt
     fi
 done
+for item in intro
+do
+    rm -f $builddir/$item.tex
+    if [ -r $booke/$item.txt ]; then
+        txt2tags --no-headers --target=tex --outfile=$builddir/$item.tex $booke/$item.txt
+    else
+        touch $builddir/$item.tex
+    fi
+done
 
 for filename in $dir/*.${papersize}.tex
 do

makeWeb.sh

@@ -38,7 +38,7 @@ if [ -r $bookedir/subtitle.txt ]; then
     subtitle=`cat $bookedir/subtitle.txt`
 fi
 if [ -r $bookedir/intro.txt ]; then
-    intro=`cat $bookedir/intro.txt`
+    intro=`txt2tags --no-headers --target=html --outfile=- $bookedir/intro.txt`
 fi
 
 if [ -n "$instrument" ]; then