Merge pull request #230 from brettcannon/patch-2

Update factorial example from using get_local to local.get

Author: fitzgen

src/what-is-webassembly.md

@@ -20,14 +20,14 @@ For reference, here is a factorial function in `wat`:
 ```
 (module
   (func $fac (param f64) (result f64)
-    get_local 0
+    local.get 0
     f64.const 1
     f64.lt
     if (result f64)
       f64.const 1
     else
-      get_local 0
-      get_local 0
+      local.get 0
+      local.get 0
       f64.const 1
       f64.sub
       call $fac