I _also_ thought this had been fixed; but Codacy is _still_ bothering me with the details. Note: my local `remark` currently doesn't complain about any other issues, so I'm re-submitting, to see if Codacy's `remark` still finds any excuse for complaining...
Appveyor uses `remark` to throw a few warnings about lack of consistency when writing Markdown text; this README.md is now rewritten according to `remark`'s guidelines.
A `LibreMetaverse.ReleaseNoGUI.sln` was included at the root to allow Linux/macOS compilations to succeed, without worrying about the GUI apps.
To-do: create a more complex dependency logic so that Windows users automatically get the GUI apps compiled by default, while these are skipped under macOS/Linux. Currently, you need to explicitly use a different solution file.
Also: added information regarding upcoming obsolescence of .NET 5.0
