doc: release notes: style update; Zephyr Kernel to Zephyr RTOS

ioannisg · ioannisg · commit 0ea5f841430d · 2019-09-06T23:34:18.000+02:00
Zephyr is more than a kernel, so we update the title of
the release notes' section accordingly.

Signed-off-by: Ioannis Glaropoulos &lt;Ioannis.Glaropoulos@nordicsemi.no&gt;
diff --git a/doc/releases/release-notes-2.0.rst b/doc/releases/release-notes-2.0.rst
@@ -2,10 +2,10 @@
 
 .. _zephyr_2.0:
 
-Zephyr Kernel 2.0.0
+Zephyr RTOS 2.0.0
 ###################
 
-We are pleased to announce the release of Zephyr kernel version 2.0.0.
+We are pleased to announce the release of Zephyr RTOS version 2.0.0.
 
 Major enhancements with this release include:
 
