update for v2

Configuration.md

@@ -1,37 +1,45 @@
-The app can be configured via the `config.json` file in the `data/` folder.
+As of version 2.x, the app can be configured via the `config.json` file in the `data/` folder.
 
 The structure of the file is:
 ```json
 {
   "randomSeed" : 20,
   "port" : 8888,
+  "address" : "0.0.0.0",
   "captchaExpiryTimeLimit" : 5,                          // in minutes
-  "throttle" : 10,
+  "bufferCount" : 10,
+  "maxAttemptsRatio": 0.01,
   "threadDelay" : 2,
+  "playgroundEnabled": true,
+  "corsHeader": "",
   "captchas" : [ {
     "name" : "FilterChallenge",
     "allowedLevels" : [ "medium", "hard" ],
     "allowedMedia" : [ "image/png" ],
     "allowedInputType" : [ "text" ],
+    "allowedSizes" : ["350x100"],
     "config" : { }
   }, {
     "name" : "GifCaptcha",
     "allowedLevels" : [ "hard" ],
     "allowedMedia" : [ "image/gif" ],
     "allowedInputType" : [ "text" ],
+    "allowedSizes" : ["350x100"],
     "config" : { }
   }, {
     "name" : "ShadowTextCaptcha",
     "allowedLevels" : [ "easy" ],
     "allowedMedia" : [ "image/png" ],
     "allowedInputType" : [ "text" ],
+    "allowedSizes" : ["350x100"],
     "config" : { }
   }, {
     "name" : "RainDropsCaptcha",
     "allowedLevels" : [ "easy", "medium" ],
     "allowedMedia" : [ "image/gif" ],
     "allowedInputType" : [ "text" ],
+    "allowedSizes" : ["350x100"],
     "config" : { }
   } ]
-}%          
+}     
 ```