feat(ci): Add release-please automation with VERSION (#2622)

* Add VERSION file that Zephyr will pick up
* Add release-please automation
* Updated docs on commits messages, and PR process
* Updated PR template to match.

---


Release-As: 0.1.0

Co-authored-by: Cem Aksoylar <caksoylar@users.noreply.github.com>

app/VERSION

@@ -0,0 +1,13 @@
+# x-release-please-start-major
+VERSION_MAJOR = 0
+# x-release-please-end
+
+# x-release-please-start-minor
+VERSION_MINOR = 0
+# x-release-please-end
+
+# x-release-please-start-patch
+PATCHLEVEL = 1
+# x-release-please-end
+
+VERSION_TWEAK = 0