[Cin] small changes in Manual

[Andrea paz]

@igor_ubuntu (Igor Vladimirsky)
See if the changes made to the manual sound good to you.
https://git.cinelerra-gg.org/git/?p=goodguy/cin-manual-latex.git;a=commitdiff;h=8da3ca92772da956388bb055696a8b564bd1212f

If that doesn't work for you, try writing something yourself (plain
text is fine) and
then put it here in the thread so it can be integrated into the manual.

If, on the other hand, what you are asking for is that every sentence
I take from your
manual report the author, then I apologize for what I have done so
far. I thought that
having asked your permission and then mentioning you on the mailing
list (complete with a
link) was enough. From now on, I will not resume sentences written by
others to avoid
these problems.