webkitgtk3: Add DESCRIPTION about API version

It took me some time to see the difference between webkitgtk and webkitgtk3.
So, give a hint in the DESCRIPTION why this recipe exists. And name the
pkgconf file for javascriptcoregtk to make it easier to find this recipe,
when you have no clue about these API versions.

Credits to Debian for lifting the fog.

https://salsa.debian.org/webkit-team/webkit/-/blob/f04cf703b06ce74bb94add3f75aa7ac5603d0eae/debian/rules#L11

Signed-off-by: Jörg Sommer <joerg.sommer@navimatix.de>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-support/webkitgtk/webkitgtk3_2.44.3.bb

@@ -1,4 +1,8 @@
 SUMMARY = "WebKit web rendering engine for the GTK+ platform"
+DESCRIPTION = "\
+    This recipe builds with Gtk3 (instead of Gtk4) which results in API version 4.1 \
+    (having javascriptcoregtk-4.1.pc instead of 6.0). \
+"
 HOMEPAGE = "https://www.webkitgtk.org/"
 BUGTRACKER = "https://bugs.webkit.org/"
 
@@ -49,6 +53,8 @@ DEPENDS += " \
           gettext-native \
           "
 
+# using soup2 builds (JavaScript) API version 4.0
+# using soup3 builds (JavaScript) API version 4.1
 PACKAGECONFIG_SOUP ?= "soup3"
 PACKAGECONFIG ??= " \
 	   ${@bb.utils.filter('DISTRO_FEATURES', 'systemd wayland x11', d)} \