correct lexer rename

lex/parse.go

@@ -10,7 +10,7 @@ import (
 //optionally followed by a colon and space and the actual contents of that element.
 //Special elements exist: newpage, titlepage and metasection.
 //These elements trigger pdf creation instructions.
-func Parse(file io.Reader) (out Screenplay) {
+func Parse(file io.Reader) (out Document) {
 	f := bufio.NewReader(file)
 	var err error
 	var s string

lex/write.go

@@ -5,7 +5,7 @@ import (
 	"io"
 )
 
-func Write(s Screenplay, out io.Writer) {
+func Write(s Document, out io.Writer) {
 	for _, line := range s {
 		fmt.Fprintf(out, "%s: %s\n", line.Type, line.Contents)
 	}