slug for output directories

main.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/davecgh/go-spew/spew"
 	"github.com/flosch/pongo2"
+	"github.com/gosimple/slug"
 	"github.com/op/go-logging"
 	cpy "github.com/otiai10/copy"
 	"gopkg.in/russross/blackfriday.v2"
@@ -155,19 +156,19 @@ func readContentDir(inBase string, outBase string, dir string, conf *PathConfig,
 			stripedDir = regex.ReplaceAllString(stripedDir, "$1")
 		}
 	}
-	regex := regexp.MustCompile("[^a-zA-Z]")
-	stripedDir = regex.ReplaceAllString(stripedDir, "_")
-	outPath := outBase + "/" + stripedDir
-	outPath = path.Clean(outPath)
-
-	log.Infof("calculated output directory: %s", outPath)
-	tree.OutputPath = outPath
 
 	if tree.Config.This.Navname == nil {
 		navname := strings.Replace(stripedDir, "_", " ", -1)
 		tree.Config.This.Navname = &navname
 	}
 
+	stripedDir = slug.Make(stripedDir)
+	outPath := outBase + "/" + stripedDir
+	outPath = path.Clean(outPath)
+
+	log.Infof("calculated output directory: %s", outPath)
+	tree.OutputPath = outPath
+
 	// first only files
 	for _, f := range files {
 		p := inPath + "/" + f.Name()