lots of fixes and additions:

- add color and color config support
- fix epub parsing
- add variable margin (left and right arrow keys)
- add help screen (hit `?`)
- add config file support

pkg/epub/content.go

@@ -0,0 +1,46 @@
+package epub
+
+import (
+	"encoding/xml"
+	"fmt"
+	"strings"
+)
+
+// Content nav-point content
+type Content struct {
+	Src   string `xml:"src,attr" json:"src"`
+	Empty bool
+	Body  string
+	Title string
+	XML   []byte
+}
+
+func (c *Content) String(content []byte) error {
+	title := Title{}
+
+	err := xml.Unmarshal(content, &title)
+	if err != nil {
+		if !strings.HasPrefix(err.Error(), "XML syntax error") {
+			return fmt.Errorf("XML parser error %w", err)
+		}
+	}
+
+	c.Title = strings.TrimSpace(title.Content)
+
+	txt := cleantitle.ReplaceAllString(string(content), "")
+	txt = cleanh1.ReplaceAllString(txt, "")
+	txt = cleanmarkup.ReplaceAllString(txt, "")
+	txt = cleanentities.ReplaceAllString(txt, " ")
+	txt = cleancomments.ReplaceAllString(txt, "")
+
+	txt = strings.TrimSpace(txt)
+
+	c.Body = cleanspace.ReplaceAllString(txt, "")
+	c.XML = content
+
+	if len(c.Body) == 0 {
+		c.Empty = true
+	}
+
+	return nil
+}