docs: reorder directory paths

Author: gunjjoshi

lib/node_modules/@stdlib/math/base/special/falling-factorial/package.json

@@ -20,8 +20,8 @@
     "doc": "./docs",
     "example": "./examples",
     "include": "./include",
-    "src": "./src",
     "lib": "./lib",
+    "src": "./src",
     "test": "./test"
   },
   "types": "./docs/types",