Make MUNGE generated table of contents (TOC) bookmark work when there are symbols in the headline

cmd/mungedocs/toc.go

@@ -75,6 +75,9 @@ func buildTOC(markdown []byte) ([]byte, error) {
 		if numSharps > 0 {
 			indent := strings.Repeat("  ", numSharps-1)
 			bookmark := strings.Replace(strings.ToLower(heading), " ", "-", -1)
+			// remove ' and ? in bookmarks
+			bookmark = strings.Replace(bookmark, "?", "", -1)
+			bookmark = strings.Replace(bookmark, "'", "", -1)
 			tocLine := fmt.Sprintf("%s- [%s](#%s)\n", indent, heading, bookmark)
 			buffer.WriteString(tocLine)
 		}