Adds godoc comments

text/segment.go

@@ -0,0 +1,17 @@
+package text
+
+import "strings"
+
+// BetweenStrings returns a string between the starting and ending string or an empty string if none could be found
+func BetweenStrings(str string, start string, end string) (result string) {
+	s := strings.Index(str, start)
+	if s == -1 {
+		return
+	}
+	s += len(start)
+	e := strings.Index(str[s:], end)
+	if e == -1 {
+		return
+	}
+	return str[s : s+e]
+}