doc: rewrite the front page

Add a link to the s.a.c doc page for high-level topics like overview,
motivation, architecture, etc.

Add more links to other docs in the repository.

Bug: N/A
Test: N/A
Change-Id: I6f84eff927f93955ed679315cd6609361ab608aa
diff --git a/README.md b/README.md
index eb28e94..3bf98f6 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,28 @@
-# Virtualization
+# Android Virtualization Framework (AVF)
 
-This repository contains userspace services related to running virtual machines on Android,
-especially protected virtual machines. See the
-[getting started documentation](docs/getting_started/index.md) and
-[Microdroid README](microdroid/README.md) for more information.
+Android Virtualization Framework (AVF) provides secure and private execution environments for
+executing code. AVF is ideal for security-oriented use cases that require stronger isolation
+assurances over those offered by Android’s app sandbox.
+
+Visit [our public doc site](https://source.android.com/docs/core/virtualization) to learn more about
+what AVF is, what it is for, and how it is structured. This repository contains source code for
+userspace components of AVF.
+
+If you want a quick start, see the [getting started guideline](docs/getting_started/index.md)
+and follow the steps there.
+
+For in-depth explanations about individual topics and components, visit the following links.
+
+AVF components:
+
+* [pVM firmware](pvmfw/README.md)
+* [Microdroid](microdroid/README.md)
+* [Microdroid kernel](microdroid/kernel/README.md)
+* [Microdroid payload](microdroid/payload/README.md)
+* [vmbase](vmbase/README.md)
+* [VM Payload API](vm_payload/README.md)
+
+How-Tos:
+* [Building and running a demo app in Java](demo/README.md)
+* [Building and running a demo app in C++](demo_native/README.md)
+* [Debugging](docs/debug)