Be clear about the efficacy/health implications of apps that filter blue light about red-moon

[smichel17]

To be completely honest, despite using this app for years, I have not spent any effort searching for or reading the relevant research. I started using Red Moon because I found it was personally helpful. That morphed into maintaining the app when I wanted to add some features and it turned out to be an easy code base to work in. I've put in less time over the years for a number of reasons, which I explained in #281.

To reflect that, I phrased the readme carefully, with these goals:

1. Avoid making any medical claims
   • …or giving a misleading impression.
2. Explain why someone might want to use the app
3. Be brief

I remember 1 and 3 being hard to balance, but I think it's currently pretty good. Still room for improvement. I'm not going to put in the time for wordsmithing myself, but I'd happily accept a PR. I think the best approach would be:

• So, swap the order of the sentences so that the first one is about Red Moon making your phone more comfortable to use at night. The first sentence has the most emphasis, so this would help avoid false impressions up front.
• In the second part, mention something along the lines of, "…although it's unclear whether a filter like Red Moon will help."
• Add a section with more detailed information and links to the studies. Mention it in the intro ("More details below").