Fix docs mentioning snake_case when refering to kebab-case

Fixes #600

doc/UsingHiccupToDescribeHTML.md

@@ -69,7 +69,7 @@ Use a string as a key for the `:style` map:
 ```
 
 NOTE: This is due to how Reagent turns keywords as map keys to Object
-properties with conversion from snake-case to camelCase, which React
+properties with conversion from kebab-case to camelCase, which React
 also uses with CSS properties (vs. regular CSS). It could be possible
 to change the implementation to skip the case-conversion for properties
 starting with `--` but it isn't implemented now.

src/reagent/core.cljs

@@ -94,7 +94,7 @@
   Everything is optional, except either :reagent-render or :render.
 
   Map keys should use `React.Component` method names (https://reactjs.org/docs/react-component.html),
-  and can be provided in snake-case or camelCase.
+  and can be provided in kebab-case or camelCase.
 
   State can be initialized using constructor, which matches React.Component class,
   or using getInitialState which matches old React createClass function and is

src/reagent/impl/component.cljs

@@ -285,7 +285,7 @@
   "Creates JS class based on provided Clojure map.
 
   Map keys should use `React.Component` method names (https://reactjs.org/docs/react-component.html),
-  and can be provided in snake-case or camelCase.
+  and can be provided in kebab-case or camelCase.
   Constructor function is defined using key `:getInitialState`.
 
   React built-in static methods or properties are automatically defined as statics."