Ask doctor and devices about the programs this system actually uses

`doctor` had the Wayland pair spelled into it, so an X11 machine was never
asked about the two it really pastes with, a Mac was told ydotool and
kwriteconfig6 were missing, and Windows, which shells out for neither half of
the clipboard, got five red marks for programs it was never going to have. The
two come out of `paste.Desktop` now, and the Linux-only three are added on
Linux. A row saying a program is missing on a machine that would never have run
it is not a diagnosis, it is a mark to explain away.

`devices` had the same shape of answer: "pactl found nothing; is PipeWire
running?" on a Windows machine with no microphone. It names whatever this sound
system is missing instead, which is the string the table already carries for it.

The Windows README's troubleshooting sends people to both, so it says so.

README.windows.md

@@ -62,8 +62,9 @@ python dikte.py
 
 ## Troubleshooting
 
-- **Recording does not start:** does `ffmpeg -version` run? Does
-  `dikte devices` list your microphone?
+- **Recording does not start:** does `dikte doctor` find ffmpeg, and does
+  `dikte devices` list your microphone? `devices` also takes a fresh listing,
+  which is what to run after plugging one in.
 - **Nothing is pasted:** a normal-privilege process cannot type into an
   elevated (administrator) window; run Dikte elevated too, or paste by hand.
   The text lands on the clipboard either way.