Add some details in features list

Author: MoOx

README.md

@@ -34,38 +34,59 @@ Follow [@cssnext on Twitter](https://twitter.com/cssnext) to get the latest news
 
 ## Features
 
-* automatic vendor prefixes ([⇗](https://github.com/postcss/autoprefixer)),
+You can safely use the following features:
+
+* automatic vendor prefixes
+(via [autoprefixer](https://github.com/postcss/autoprefixer)),
 * [custom properties & `var()`](http://www.w3.org/TR/css-variables/)
-([⇗](https://github.com/postcss/postcss-custom-properties)) limited to `:root`,
+limited to `:root`
+([⇗](https://github.com/postcss/postcss-custom-properties)),
 * [reduced `calc()`](https://github.com/MoOx/reduce-css-calc#readme)
-([⇗](https://github.com/postcss/postcss-calc)) to optimize previously parsed `var()` references,
+to optimize previously parsed `var()` references
+([⇗](https://github.com/postcss/postcss-calc)),
 * [custom media queries](http://dev.w3.org/csswg/mediaqueries/#custom-mq)
-([⇗](https://github.com/postcss/postcss-custom-media)) a nice way to have semantic media queries,
+a nice way to have semantic media queries
+([⇗](https://github.com/postcss/postcss-custom-media)),
 * [media queries ranges](http://dev.w3.org/csswg/mediaqueries/#mq-ranges)
-([⇗](https://github.com/postcss/postcss-media-minmax)) that allows to replace min-/max- with `<=` & `>=` (syntax easier to read),
+that allows to replace min-/max- with `<=` & `>=` (syntax easier to read)
+([⇗](https://github.com/postcss/postcss-media-minmax)),
 * [custom selectors](http://dev.w3.org/csswg/css-extensions/#custom-selectors)
-([⇗](https://github.com/postcss/postcss-custom-selector)) to create your own selectors,
+to create your own selectors
+([⇗](https://github.com/postcss/postcss-custom-selector)),
 * [`color()`](http://dev.w3.org/csswg/css-color/#modifying-colors)
-([⇗](https://github.com/postcss/postcss-color-function)) a color function to modify colors,
+a color function to modify colors
+(transpiled to: `rgba()`)
+([⇗](https://github.com/postcss/postcss-color-function)),
 * [`hwb()`](http://dev.w3.org/csswg/css-color/#the-hwb-notation)
-([⇗](https://github.com/postcss/postcss-color-hwb)) similar to `hsl()` but easier for humans to work with,
+similar to `hsl()` but easier for humans to work with
+(transpiled to: `rgba()`)
+([⇗](https://github.com/postcss/postcss-color-hwb)) ,
 * [`gray()`](http://dev.w3.org/csswg/css-color/#grays)
+(transpiled to: `rgba()`)
 ([⇗](https://github.com/postcss/postcss-color-gray)),
 * [#rrggbbaa](http://dev.w3.org/csswg/css-color/#hex-notation)
+(transpiled to: `rgba()`)
 ([⇗](https://github.com/postcss/postcss-color-hex-alpha)),
 * [`rebeccapurple`](http://dev.w3.org/csswg/css-color/#valdef-color-rebeccapurple)
 ([⇗](https://github.com/postcss/postcss-color-rebeccapurple)),
-* [font-variant](http://dev.w3.org/csswg/css-fonts/#propdef-font-variant) properties
+* [font-variant](http://dev.w3.org/csswg/css-fonts/#propdef-font-variant)
+properties (fallback: `font-feature-settings`)
 ([⇗](https://github.com/postcss/postcss-font-variant)),
-* [filter](http://www.w3.org/TR/filter-effects/) properties
+* [filter](http://www.w3.org/TR/filter-effects/)
+properties (fallback: inlined `<svg>` filter)
 ([⇗](https://github.com/iamvdo/pleeease-filters))
-* [rem](http://www.w3.org/TR/css3-values/#rem-unit) units
+* [`rem` units](http://www.w3.org/TR/css3-values/#rem-unit)
+(fallback: `px`)
 ([⇗](https://github.com/robwierzbowski/node-pixrem))
 * [pseudo-elements](http://www.w3.org/TR/css3-selectors/#pseudo-elements)
+(adjust `::` to `:`)
 ([⇗](https://github.com/axa-ch/postcss-pseudoelements))
-* [rgba()](http://www.w3.org/TR/css3-color/)
+* alpha colors for browser that don't understand [css 3 colors](http://www.w3.org/TR/css3-color/)
+(fallback: solid hexa colors)
 ([⇗](https://github.com/postcss/postcss-color-rgba-fallback))
 
+_Note that according to your [browser scope](#nodejs-options) some might be not transpiled to avoid extra useless output._
+
 ### Bonus features
 
 _<small>The features below are considered as bonus since it's totally not related to CSS specs</small>._