Update create-class doc strings

src/reagent/core.cljs

@@ -103,8 +103,7 @@
   (batch/flush-after-render))
 
 (defn create-class
-  "Create a component, React style. Should be called with a map,
-  looking like this:
+  "Creates JS class based on provided Clojure map, for example:
 
   ```cljs
   {:get-initial-state (fn [this])
@@ -118,7 +117,13 @@
    :reagent-render (fn [args....])}   ;; or :render (fn [this])
   ```
 
-  Everything is optional, except either :reagent-render or :render."
+  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.
+  Constructor function is defined using key `:get-initial-state`.
+
+  React built-in static methods or properties are automatically defined as statics."
   [spec]
   (comp/create-class spec))
 

src/reagent/impl/component.cljs

@@ -98,6 +98,9 @@
   [c]
   (let [f (.-reagentRender c)
         _ (assert-callable f)
+        ;; cljsLegacyRender tells if this calls was defined
+        ;; using :render instead of :reagent-render
+        ;; in that case, the :render fn is called with just `this` as argument.
         res (if (true? (.-cljsLegacyRender c))
               (.call f c c)
               (let [v (get-argv c)
@@ -284,7 +287,8 @@
 (defn create-class
   "Creates JS class based on provided Clojure map.
 
-  Map keys should use `React.Component` method names (https://reactjs.org/docs/react-component.html).
+  Map keys should use `React.Component` method names (https://reactjs.org/docs/react-component.html),
+  and can be provided in snake-case or camelCase.
   Constructor function is defined using key `:getInitialState`.
 
   React built-in static methods or properties are automatically defined as statics."