Tighten up language around badges on README

On #82 (comment) we
decided to refer to "badges by Shields." We're not trying to change the
name of the thing itself to a "shield."

README.md

@@ -2,7 +2,7 @@
 
 A legible & concise status badge solution for third-party codebase services. Soon to be Retina-ready.
 
-![shields on white](https://raw.github.com/badges/shields/master/static/shields_white.png)
+![badges on white](https://raw.github.com/badges/shields/master/static/shields_white.png)
 
 ## Services using Shields
 - [Code Climate](https://codeclimate.com/changelog/510d4fde56b102523a0004bf)
@@ -36,9 +36,9 @@ As you can see from the zoomed 400% versions of these badges above, nobody is (r
 ## Solution
 As you can see below, without increasing the footprint of these badges, I've tried to increase legibility and coherence, removing useless text to decrease the horizontal length in the (likely) scenario that more of these badge thingies crop up on READMEs all across the land.
 
-![shields on white](https://raw.github.com/badges/shields/master/static/shields_white.png)
+![badges on white](https://raw.github.com/badges/shields/master/static/shields_white.png)
 
-![shields on black](https://raw.github.com/badges/shields/master/static/shields_black.png)
+![badges on black](https://raw.github.com/badges/shields/master/static/shields_black.png)
 
 Thanks to @ackerdev we also have SVG equivalents of all existing badges if you would like your badges to be Retina-ready or dynamically manipulate the text inside of them before you output them to PNG 24 Alpha (transparent background).
 
@@ -74,9 +74,9 @@ What kind of meta data can you convey using Shields badges?
 - amount of [gittip](http://gittip.com) donations per week: `tips | $2/week`
 
 ## Retina Ready
-Since one of the major concerns is legibility, it's impossible to ignore how bad shields will look on retina (high DPI) displays.
+Since one of the major concerns is legibility, it's impossible to ignore how badges will render on retina (high DPI) displays.
 
-A suggested by @kneath, Shields displayed with an HTML image tag (instead of the easier Markdown image tag) can be given a fixed height to force an image that is actually double the resolution into a 50% smaller image, which will display properly for both retina and non-retina screens.
+A suggested by @kneath, Shields badges displayed with an HTML image tag (instead of the easier Markdown image tag) can be given a fixed height to force an image that is actually double the resolution into a 50% smaller image, which will display properly for both retina and non-retina screens.
 
 Here's an example with the following code: 
 
@@ -86,14 +86,14 @@ Here's an example with the following code:
 
 <img src="https://raw.github.com/badges/shields/master/static/shields_white@2x.png" height="143" alt="Retina-ready Shields example" />
 
-All shields aren't yet compatible with this but we're working on updating them soon. Look for image filenames with `@2x` suffixes, those will be the pixel doubled versions. 
+All Shields badges aren't yet compatible with this but we're working on updating them soon. Look for image filenames with `@2x` suffixes, those will be the pixel doubled versions. 
 
 Note: They were pixel doubled manually in Photoshop, not after the fact.
 
 ## Font
 The font used on these badges is the Apache licensed Open Sans Regular available from [Google Web Fonts](http://www.google.com/webfonts/specimen/Open+Sans).
 
-## How to resize a Shield
+## How to resize a badge 
 
 Want to use one of these swanky badges for your own service right now and don't have time to [open an issue](https://github.com/gittip/shields.io/issues) and wait for us to help you out?