what-i-wish-id-known.rst: replace figure by the new SVG

We have a new SVG figure for the Yocto Project workflow figure, which
was updated with d2aaf54bee49 ("overview-manual: convert
YP-flow-diagram.png to SVG"). The one in the "What I wish I’d known
about Yocto Project" is the same. Remove the PNG and make a reference to
the new one.

(From yocto-docs rev: ef4b9077c04ed825890abf79848f45d8e692bbf7)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
(cherry picked from commit 4023c47cb6628971b0a142067c4a910420408bb9)
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/what-i-wish-id-known.rst

@@ -98,7 +98,7 @@ contact us with other suggestions.
    function of a particular part of the workflow gives you an idea of what might
    be going wrong.
 
-   .. image:: figures/yp-how-it-works-new-diagram.png
+   .. image:: overview-manual/svg/yp-flow-diagram.*
       :width: 100%
 
 #. **Know that you can generate a dependency graph and learn how to do it:**