Update Buttons README.

Summary: This CL updates the Buttons' README file with the feedback received.

Test Plan: Check for typo and valid Markdown in the touched file.

Reviewers: featherless, #material_components_ios_owners, ajsecord

Reviewed By: #material_components_ios_owners, ajsecord

Subscribers: featherless

Projects: #material_components_ios_owners

Differential Revision: http://codereview.cc/D71

Author: Arcank

components/Buttons/README.md

@@ -1,31 +1,30 @@
 # Buttons
 
-A collection of material buttons, including a Flat button, a Raised button and a Floating button.
+Buttons is a collection of material buttons, including a flat button, a raised button and a floating
+action button.
 
-The Flat button does not have its own background color and does not raise when touched. A Flat
-button should be used in most situations requiring a button.
+The flat button does not have its own background color and does not raise when touched. Use a flat
+button in most situations requiring a button.
 
-The Raised button has its own background color, floats above its parent slightly, and raise briefly
-when touched. A Raised button should be used when a Flat button would get lost among other UI
-elements on the screen.
+The raised button has its own background color. It floats above its parent slightly, and raises
+briefly when touched. A raised button should be used when a flat button would get lost among other
+UI elements on the screen.
 
-A Floating button is circular, floats a considerable amount above its parent, has its own background
-color, and also raises briefly when touched. A Floating button should only be used for the main
-action of a screen.
+The floating action button is circular, floats a considerable amount above its parent, has its own
+background color, and also raises briefly when touched. Only use a floating action button for the
+main action of a screen.
 
 All buttons display animated ink splashes when the user interacts with the button.
 
 For non-flat buttons, the background color is determined from the enabled, disabled-light, and
 disabled-dark background color properties. Flat buttons have a transparent background.
 
 When disabled, material buttons take on a specific semi-transparent appearance which depends on
-whether the button is on a light background or a dark background. To ensure this works correctly,
-the owner is responsible for setting (and updating, if necessary), the button's underlyingColor
-property for all buttons.
+whether the button is on a light background or a dark background.
 
-The title color of the button should be set to have an accessible contrast ratio with the button's
-background color. To ensure this works for Flat buttons, the caller is responsible for setting (and
-updating, if necessary) the button's underlyingColor property for flat buttons.
+Set the title color of the button to have an accessible contrast ratio with the button's background
+color. The caller is responsible for setting (and updating, if necessary) the button's
+underlyingColor property for flat buttons.
 
 All buttons set the exclusiveTouch property to YES by default, which prevents users from
 simultaneously interacting with a button and other UI elements.