sync: import files in markdown, relative to theme/exercice dir

libfic/theme_export.go

@@ -3,6 +3,7 @@ package fic
 import (
 	"fmt"
 	"path"
+	"strings"
 )
 
 // exportedExercice is a structure representing a challenge, as exposed to players.
@@ -63,7 +64,7 @@ func ExportThemes() (interface{}, error) {
 					theme.URLId,
 					theme.Authors,
 					theme.Headline,
-					theme.Intro,
+					strings.Replace(theme.Intro, "$FILES$", FilesDir, -1),
 					imgpath,
 					exos,
 				}