Add README and a screenshot

Signed-off-by: Justin Kim <[email protected]>

README.md

@@ -0,0 +1,48 @@
+Example Android App for AHCSRC
+==============================
+
+Prerequisite
+------------
+
+ - Gstreamer SDK for Android (>=1.7.1)
+ - Android Studio (>=2.3.3)
+ - Android NDK (>=r15b)
+ - Gradle (>=2.3.3)
+
+Build and Installation
+----------------------
+
+ - Set GSTREAMER_ROOT_ANDROID evironment varible
+
+```
+  $ export GSTREAMER_ROOT_ANDROID=/path/to/gstreamer/sdk
+```
+
+ - Create `local.properties` and add `sdk.dir` and `ndk.dir` properties
+
+ - Build with gradle
+
+```
+  $ gradle build
+```
+
+ - Install with gradle
+
+```
+  $ gradle installDebug
+```
+
+Screenshots
+----------
+![screenshot](screenshots/screenshot.png)
+
+Restrictions and Known bugs
+---------------------------
+
+ - ahcsrc element is a child element of GstPushSrc so it cannot be compatible
+   with camerabin2 as it is.
+
+ - No properties to set camera options like resolution, video formats.
+   Each option can be set by caps filter.
+   The options of real camera may vary on different android devices, so
+   supported options should be analyzed on android application side.