Update README about RecyclerView integration (#191)

README.md

@@ -8,12 +8,24 @@ FlexboxLayout is a library project which brings the similar capabilities of
 ## Installation
 Add the following dependency to your `build.gradle` file:
 
+Stable
 ```
 dependencies {
     compile 'com.google.android:flexbox:0.2.5'
 }
 ```
 
+OR
+
+Alpha including RecyclerView integration
+```
+dependencies {
+    compile 'com.google.android:flexbox:0.3.0-alpha1'
+}
+```
+See the [RecyclerView integration](RecyclerView.md) page for more details about using Flexbox inside
+the `RecyclerView`.
+
 ## Usage
 FlexboxLayout extends the ViewGroup like LinearLayout and RelativeLayout.
 You can specify the attributes from a layout XML like:

RecyclerView.md

+# RecyclerView integration
+
+With the latest alpha version of the release, Flexbox can now be used inside the `RecyclerView`
+as a `LayoutManager` (`FlexboxLayoutManager`).
+That means now you can use Flexbox with large number of items in a scrollable container!
+
+![FlexboxLayoutManager in action](/assets/flexbox-layoutmanager.gif)
+
+
+## Supported attributes / features comparison
+Due to some characteristics of the RecyclerView, some Flexbox attributes are not avaiable/not implemented
+to the `FlexboxLayoutManager`.
+Here is a quick overview of the attributes/features comparison between the two containers.
+
+|Attribute / Feature|FlexboxLayout| FlexboxLayoutManager (RecyclerView)|
+| ------- |:-----------:|:----------------------------------:|
+|flexDirection|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|flexWrap|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png) (except `wrap_reverse`)|
+|justifyContent|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|alignItems|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|alignContent|![Check](/assets/pngs/check_green_small.png)| - |
+|layout_order|![Check](/assets/pngs/check_green_small.png)| - |
+|layout_flexGrow|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|layout_flexShrink|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|layout_alignSelf|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|layout_flexBasisPercent|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|layout_(min/max)Width|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|layout_(min/max)Height|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|layout_wrapBefore|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|Divider|![Check](/assets/pngs/check_green_small.png)|![Check](/assets/pngs/check_green_small.png)|
+|View recycling| - |![Check](/assets/pngs/check_green_small.png)|
+|Scrolling| *1 |![Check](/assets/pngs/check_green_small.png)|
+
+*1 Partially possible by wrapping it with `ScrollView`. But it isn't likely to work with large set
+   of views inside the layout. Because it doesn't consider view recycling.
+
+
+## Backward-imcompatible changes from the 0.2.x versions
+`FlexboxLayout` can still be used as the same way, but there are some backward-imcompatible
+changes introduced.
+
+* Now Flexbox specific constants are now defined in each individual class such as:
+  * `FlexboxLayout.FLEX_DIRECTION_ROW` -> `FlexDirection.ROW`
+  * `FlexboxLayout.FLEX_WRAP_WRAP` -> `FlexWrap.WRAP`
+  * `FlexboxLayout.JUSTIFY_CONTENT_FLEX_START` -> `JustifyContent.FLEX_START`
+  * `FlexboxLayout.ALIGN_ITEMS_FLEX_START` -> `AlignItems.FLEX_START`
+  * `FlexboxLayout.ALIGN_CONTENT_FLEX_START` -> `AlignContent.FLEX_START`
+
+  including other values (such as FLEX_END, STRETCH) are now moved to each individual class.
+
+## Sample code
+The code for the new `FlexboxLayoutManager` hasn't merged to the master branch yet, since
+it's not as stable as the existing `FlexboxLayout`.
+But you can still reference some sample code using the `FlexboxLayoutManager` inside the
+`RecyclerView` in the [dev_recyclerview](https://github.com/google/flexbox-layout/tree/dev_recyclerview) branch
+such as:
+  -  [Playground demo app](https://github.com/google/flexbox-layout/tree/dev_recyclerview/demo-playground)
+  -  [Cat Gallery demo app](https://github.com/google/flexbox-layout/tree/dev_recyclerview/demo-cat-gallery)
+