Reorganize directories (#3462)

* 🚚 move files
* 🚚 rename doc folder to docs
* 🚚 rename test folder to tests

docs/examples/parse__istream__parser_callback_t.output

@@ -0,0 +1,34 @@
+{
+    "Image": {
+        "Animated": false,
+        "Height": 600,
+        "IDs": [
+            116,
+            943,
+            234,
+            38793
+        ],
+        "Thumbnail": {
+            "Height": 125,
+            "Url": "http://www.example.com/image/481989943",
+            "Width": 100
+        },
+        "Title": "View from 15th Floor",
+        "Width": 800
+    }
+}
+
+{
+    "Image": {
+        "Animated": false,
+        "Height": 600,
+        "IDs": [
+            116,
+            943,
+            234,
+            38793
+        ],
+        "Title": "View from 15th Floor",
+        "Width": 800
+    }
+}