Add an example for "timestamp" in the documentation-Authentication section

[Nanda Arfan Hakim]

There is ambiguity as to the value to be assigned to the "timestamp" used for the "construct authorization key" and for the "x-nodeflux-timestamp".

To construct authorization key uses the first 8 characters of the timestamp obtained from the Signature Request response (e.g 20210913), while the value for the key "x-nodeflux-timestamp" uses the full character timestamp obtained and there is no example for this.

Existing information is still not clear enough, maybe adding an example for this can make it more clear.

[Gregorius Jimmy]

Penambahan example bisa sekalian example bagian configure environtment header khususnya bagian Authorization. Authorization yang sudah di construct itu seperti apa. Soalnya pas pertama kali explore gw masih i have no idea yang dimaksud "Construct" itu apa

dan ini mungkin bisa diperjelas menjadi "The authorization key you have constructed"
or
Penggunaan kata construct kurang general dan bisa di ganti dengan kata "create"

[Alfin Syafalni]

related issue #12