Fix preposition capitalization

docs/07.1-more-about-refs.md

@@ -26,7 +26,7 @@ Consider the case when you wish to tell an `<input />` element (that exists with
       return (
         <div>
           <div onClick={this.clearAndFocusInput}>
-            Click To Focus and Reset
+            Click to Focus and Reset
           </div>
           <input
             value={this.state.userInput}
@@ -102,7 +102,7 @@ It's as simple as:
       return (
         <div>
           <div onClick={this.clearAndFocusInput}>
-            Click To Focus and Reset
+            Click to Focus and Reset
           </div>
           <input
             ref="theInput"