Web:Background: Reword introductory paragraph (issue 48360044)

[lilyliska]

Reviewers: ,

Description:
Web:Background: Reword introductory paragraph

I've always found this page confusing because I didn't understand
why there is this "placeholder" page.
This commit addresses this by making the "manual" issue explicit.

Additionally I consider it more useful to _first_ tell the reader
what it is and _then_ advise him to skip the essay instead of
_immediately_ telling him "Probably you won't want to read this".
If it is necessary to have the link at the end of a paragraph
(and not only of a sentence) I'd simply insert a new paragraph
after the link.

Please review this at https://codereview.appspot.com/48360044/

Affected files (+5, -3 lines):
  M Documentation/web/introduction.itexi


Index: Documentation/web/introduction.itexi
diff --git a/Documentation/web/introduction.itexi  
b/Documentation/web/introduction.itexi
index  
5d2f8c629d039c7d04a02404a8c0773d89fb65fc..0a5e2d482f2e362f2f462ba1daeb4a7a7467c9f3  
100644
--- a/Documentation/web/introduction.itexi
+++ b/Documentation/web/introduction.itexi
@@ -551,9 +551,11 @@ LilyPond, first read about our @ref{Text input}.
 We have an extensive essay describing computational aesthetics:
 the art of creating beauty with a computer.

-If you just want a quick introduction to LilyPond, the essay might
-be too much material to read.  If you would like to read it now,
-please progress to @ref{Essay}.
+This is interesting reading if you are interested in an in-depth
+discussion of our fundamental ideas.  Due to its volume the
+essay is available as a "manual".  If you would like to read
+it now, please progress to @ref{Essay}.  However, if you just
+want a quick introduction to LilyPond, you might skip it for now.
 @divEnd

 @divClass{column-center-bottom}