Doc: avoid implicit \relative; issue 4371 (issue 237340043 by address@hidden)

[tdanielsmusic]

I'm not opposed to the change to explicit \relative; it avoids having to
explain why it was omitted in the examples, and makes the example code
more exactly correspond to the code obtained by clicking on the image.
But I think if are to make this change it would also be good to say what
leaving out \relative means.  It was difficult to do this before as all
the examples left it out (apparently).  Now we can do it.  Placing a
brief explanation at the beginning of 1.2.1 would explain the mysterious
's in those first examples of code.


https://codereview.appspot.com/237340043/diff/10006/Documentation/learning/tweaks.itely
File Documentation/learning/tweaks.itely (right):

https://codereview.appspot.com/237340043/diff/10006/Documentation/learning/tweaks.itely#newcode2124
Documentation/learning/tweaks.itely:2124: \relative c' {
no leading spaces

https://codereview.appspot.com/237340043/