bug#48504: Improve style of C-h t description (Preface)

[Sebastian Urban]

Currently, in the Preface of the Emacs manual (EMACS.TEXI - L1291),
there is:
   To run the tutorial, start Emacs and type @kbd{C-h t} (which is
   ``control h and then t'').

I think, the part between parens should look better, e.g. similar to
this part of SCREEN.TEXI (L126):
   ...(hold down @key{Ctrl} and type @kbd{x}, then let go of
   @key{Ctrl} and type @kbd{=})...
...i.e.:
   ...(hold down @key{Ctrl} and type @kbd{h}, then let go of
   @key{Ctrl} and type @kbd{t}).

That's all.

--
S. U.