Franky: added installation instructions.

TBR=cmasso@google.com
BUG=716146

Change-Id: I28b3234b4a09605133f2e0ba2362120e344c0686
diff --git a/README.md b/README.md
index 356ffe7..d08d13e 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,42 @@
 to a user, including objects that are not part of the application (system
 settings, user accounts, etc).
 
-Franky is written in Python, and depends on Appium and WebDriverAgent.
+Franky is written in Python, and depends on [Appium] and
+[WebDriverAgent] (for iOS device testing).
+
+[Appium]: https://github.com/appium/appium
+[WebDriverAgent]: https://github.com/facebook/WebDriverAgent
+
+## Installation
+
+First, install [Appium]:
+
+    npm install -g appium
+
+Follow their installation instructions for your platform. In
+particular, pay close attention to iOS requirements. You may need to
+find the [WebDriverAgent] copy in the Appium installation and update
+its `WebDriverAgent.xcodeproj` with your provisioning profile and
+signing credentials.
+
+It is highly recommended to install Franky in a separate `virtualenv`
+environment:
+
+    mkdir ~/virtualenv
+    cd ~/virtualenv
+    virtualenv franky
+    source franky/bin/activate
+    cd ~
+    git clone https://chromium.googlesource.com/chromium/src/tools/franky
+    cd franky
+    ./setup.py install
+
+This will install a new command `franky` in
+`~/virtualenv/franky/bin`. You can test it by running:
+
+    franky --help
+
+## Components
 
 Franky consists of 4 main components: