Added sha256Hex function

[vfoucault]

this will compute the sha256 hash function and output the hex version
of it.

tests and doc updated.

how to use:

{{ "bladibla" | sha256Hex }}

this will output

54cf4c66bcabb5c20e25331c01dd600b73369e97a947861bd8d3a0e0b8b3d70b

[hashicorp-cla]

All committers have signed the CLA.

[eikenb]

Hey @vfoucault, thanks for the PR.

I'll most likely accept this but I'm curious... what is the use case?

[vfoucault]

Hey @eikenb, the main goal is to obviously generate sha256 of passwords. I use it in the analytics data named Clickhouse.

<?xml version="1.0"?>
<yandex>
    <users>
        <default>
            <password_sha256_hex>54cf4c66bcabb5c20e25331c01dd600b73369e97a947861bd8d3a0e0b8b3d70b</password_sha256_hex>
            <networks incl="networks" replace="replace">
                <ip>::/0</ip>
            </networks>
            <profile>default</profile>
            <quota>default</quota>
        </default>
    </users>
</yandex>

The password could be also stored in plaintext, but this is less sexy and secure !