notes doc: split up run-on sentences

When commit c4e2aa7 (notes.c: introduce "--[no-]stripspace" option,
2023-05-27) mentioned the new `--no-stripspace` in the documentation for
`-m` and `-F`, it created run-on sentences. It also used slightly
different language in the two sections for no apparent reason. Split the
sentences in two to improve readability, and while touching the two
sites, make them more similar.

Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: Martin Ågren

Documentation/git-notes.txt

@@ -141,17 +141,16 @@ OPTIONS
 	If multiple `-m` options are given, their values
 	are concatenated as separate paragraphs.
 	Lines starting with `#` and empty lines other than a
-	single line between paragraphs will be stripped out,
-	if you wish to keep them verbatim, use `--no-stripspace`.
+	single line between paragraphs will be stripped out.
+	If you wish to keep them verbatim, use `--no-stripspace`.
 
 -F <file>::
 --file=<file>::
 	Take the note message from the given file.  Use '-' to
 	read the note message from the standard input.
 	Lines starting with `#` and empty lines other than a
-	single line between paragraphs will be stripped out,
-	if you wish to keep them verbatim, use with
-	`--no-stripspace` option.
+	single line between paragraphs will be stripped out.
+	If you wish to keep them verbatim, use `--no-stripspace`.
 
 -C <object>::
 --reuse-message=<object>::