Documentation update

README.md

@@ -4,6 +4,7 @@
 [![GitHub issues](https://img.shields.io/github/issues/T-PWK/go-fibonacci.svg)](https://github.com/T-PWK/go-fibonacci/issues)
 [![Go Report Card](https://goreportcard.com/badge/github.com/T-PWK/go-fibonacci)](https://goreportcard.com/report/github.com/T-PWK/go-fibonacci)
 [![Coverage Status](https://coveralls.io/repos/github/T-PWK/go-fibonacci/badge.svg?branch=master)](https://coveralls.io/github/T-PWK/go-fibonacci?branch=master)
+[![GoDoc](https://godoc.org/github.com/T-PWK/go-fibonacci?status.svg)](https://godoc.org/github.com/T-PWK/go-fibonacci)
 [![GitHub license](https://img.shields.io/badge/license-MIT-blue.svg)](https://blog.abelotech.com/mit-license/)
 
 In mathematics, the Fibonacci numbers are the numbers in the following integer sequence, called the Fibonacci sequence, and characterized by the fact that every number after the first two is the sum of the two preceding ones:

fib.go

@@ -4,7 +4,7 @@ import "math/big"
 
 // Fibonacci calculates Fibonacci number.
 // This function generated correct values from 0 to 93 sequence number.
-// For bigger values use FibonacciBig function
+// For bigger values use FibonacciBig function.
 func Fibonacci(n uint) uint64 {
 	if n <= 1 {
 		return uint64(n)
@@ -20,7 +20,7 @@ func Fibonacci(n uint) uint64 {
 }
 
 // FibonacciBig calculates Fibonacci number using bit.Int.
-// For the sequence numbers below 94, it is recommended to use Fibonacci function.
+// For the sequence numbers below 94, it is recommended to use Fibonacci function as it is more efficient.
 func FibonacciBig(n uint) *big.Int {
 	if n <= 1 {
 		return big.NewInt(int64(n))