add README.md

BUG=
R=abarth@chromium.org

Review URL: https://codereview.chromium.org/695963003

framework/README.md

@@ -0,0 +1,52 @@
+SkyElement
+===
+
+SkyElement is the framework for creating...yup...Sky Elements. It take heavy
+inspriation from [Polymer](www.polymer-project.org) and isn't very fully
+featured...yet
+
+Declaring an element
+--------
+```HTML
+<link rel="import" href="../path/to/sky-element.sky" as="SkyElement" />
+<template>
+  <my-other-element>Hello, {{ place }}</my-other-element>
+</template>
+<script>
+// SkyElement takes a single object as it's only parameter
+SkyElement({
+  name: 'my-element', // required. The element's tag-name
+  attached: function() {
+    this.place = 'World';
+  }, // optional
+  detached: function() {}, // optional
+  attributeChanged: function(attrName, newValue, oldValue) {} // optional
+});
+</script>
+```
+
+Note that an element's declared ShadowDOM is the previous <template>
+element to the <script> element which defines the element.
+
+Databinding
+--------
+SkyElement's databinding support is derived from Polymer's. At the moment,
+there are some key differences:
+
+There is not yet support for
+ * Declarative event handlers
+ * Inline expressions
+ * Self-observation (e.g. fooChanged() gets invoked when this.foo is changed)
+ * Computed properties (e.g. the computed block)
+ * Conditional attributes (e.g. `<my-foo checked?="{{ val }}" `)
+
+ Also, because there are so few built-in elements in Sky, the default behavior
+ of HTMLElement with bindings is to assign to the property. e.g.
+
+ ```HTML
+ <my-foo bar="{{ bas }}">
+ ```
+
+ Will not setAttribute on the my-foo, instead it will assign to the `bar`
+ property of `my-foo`. There are two exceptions to this: `class` & `style` --
+ those still`setAttribute`.