Capitalize both words in Lightning Network

[stackingsaunter]

Hey, this is my first PR ever so I appreciate any feedback how I can improve my contributing in the future!

Currently we use "Lightning network" and "lightning network" in some places as well. I suggest capitalising both words in Lightning Network. It is the way it is used the most, makes it more intuitive to understand alongside abbreviations like LN or LND and is advised by Optech Style Guide. That is also how it was written in the original Lightning Network paper.

I additionally included three minor changes. Should it be a separate PR?

• In Units and symbols's Interactive formatter change Polen to english Poland and use polish currency PLN
• Unlink Morruci survey from Getting to know your users as the research is not conducted anymore. Also link straight to PDF results not github page in the Design Research section
• Change "But unlike your bank, bitcoin has never been hacked." to "But unlike many bank, bitcoin has never been hacked.". I found this sentence quite strange, as my bank was never hacked ;)

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[danielnordh]

Thanks for the contribution Jakub!

When it comes to topics that may require some discussion, it's normally a good idea to open an issue before going ahead with a PR. This is mostly to save yourself work in case the discussion concludes with a differing view.

And yes, it is good practice to separate PRs so that it only covers one thing at a time.

In terms of the actual suggestion here, adopting Lightning Network in capitals everywhere, I am not in favor of this.
I'm basing my opinion on similar thoughts as in the discussion about Bitcoin vs bitcoin #635

In addition, I don't like calling out the lightning network in a way that comes across as 'branded' and extra important when it is capitalized: Lightning Network. The focus should as much as possible be on bitcoin, and lightning is a supporting subset of bitcoin technology (that should be less and less important to know by name over time IMO).

My suggestion to the problem of it being using in mixed case throughout the guide would be to use lower case everywhere:

I.e. bitcoin and the lightning network.