[Info Update] Update bounties page to highlight the Tax status requirements

[SimonDarksideJ]

Link to Document

https://github.com/MonoGame/monogame.github.io/blob/main/website/content/bounties.njk

Description

The Tax declarations the MonoGame Foundation requires for the non-profit status needs highlighting more to make it clear on the requirements.

As well as highlighting the need to comply with US Trade Restrictions.

A note is also needed that acceptance can also be given if the author wants to waive the bounty funding.

[SimonDarksideJ]

@AristurtleDev when you get a sec, I cannot seem to get admonitions working on the bounties page. We need to add these two call outs

    ::: tip Apply before starting
    To ensure work is not duplicated and effort is not lost, we ask that all Bounty applicants apply "BEFORE" starting work.  THIs ensures the conditions for the bounty are met and than multiple developers do not start working simultaneously where only one solution can be accepted.

    We appreciate everyone's efforts and do not want to see anything wasted.
    :::  

and

    ::: warning Tax emption status and US trade laws
    As MonoGame is a US based non-profit organisation, as such we have to comply with US Trade restrictions and tax indemnifications, as such we are required to adhere to the following:

    * All paid commissions must be paired with the above W8/9 tax status, for the organisation to qualify for tax exemption.
    * We cannot pay out to any individual or organisation on the US Trade Exemption list.  We can still accept contributions from developers based in these regions, we just cannot pay for it. 

    We ask you keep this in mind when applying to bounties.
    :::