README: simplify intro

Style guide recommends having the intro be merged into the first
section & before the TOC so it's easier to read.

BUG=None
TEST=read the doc

Change-Id: I4e12bd1e1def696ee38adda7a86716d13a40a186
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2686111
Reviewed-by: Stephane Belmon <sbelmon@google.com>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/README.md b/README.md
index 18c4928..d3a4db7 100644
--- a/README.md
+++ b/README.md
@@ -1,12 +1,10 @@
 # Chromite Development: Starter Guide
 
-[TOC]
-
-## Objective
-
 This doc tries to give an overview and head start to anyone just starting out on
 Chromite development.
 
+[TOC]
+
 ## Background
 
 Before you get started on Chromite, we recommend that you go through ChromeOS