update: Tidy up Cryptocurrency page and recommend places to buy Monero

[eylenburg]

List of changes proposed in this PR:

The main change is adding some recommendations for where to buy Monero. This a list of various reputable places with different requirements (Kraken: KYC ok; Cake Wallet: avoid KYC; RetoSwap: P2P and no country restrictions).

I also added some sub-headings for wallets and nodes and put the comments about Monero's resilience in a summary+detail box.

Finally, some cross-linking between the advanced/payments.md and the cryptocurrency.md pages.

I have just written this in Markdown so hopefully the end result will render correctly. Also happy for to make changes, this is just a first draft.

[privacyguides-bot]

This pull request has been mentioned on Privacy Guides Community. There might be relevant details there:

https://discuss.privacyguides.net/t/suggestion-elaborate-how-to-get-monero/16817/15

[github-actions]

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[eylenburg]

Seems like the geographical restrictions admonition box and the footnotes are not formatted correctly. How do I fix it?

[SamsungGalaxyPlayer]

Thank you for your suggestions! I kindly request that we wait until MAGIC Grants can do a legal review of proposed money/cryptocurrency PRs before merging, due to the sensitivity of some related laws. This is something we should get to this weekend or early next week. Thank you for your understanding!

[eylenburg]

Thank you that's absolutely no problem.

By the way, Kraken and Cake Wallet are mentioned on the website currently (in advanced/payments.md and cryptocurrency.md respectively). Only Reto is new but seems to be the "go-to" recommendation in the Monero community since LocalMonero shut down.

[SamsungGalaxyPlayer]

@eylenburg please check to see if you have any questions or concerns with the changes. Thanks!

[redoomed1]

The internal links for the Notices and Disclaimers page on each edited page are broken, which need to be fixed before merging.

[eylenburg]

New website for Retoswap is online now: https://retoswap.com/

missing suggestion

[redoomed1]

The only minor suggestion I have for you is to replace the old RetoSwap URL with the new one you posted earlier.

Otherwise, this PR looks good to me. Thanks y'all!

Suggested changes have been applied

[redoomed1]

These suggested changes attempt to streamline the info about geographical restrictions and avoid unnecessary maintenance burden as hinted by Jonah here.