Remove Duolingo. Usernames that don't exist are detected.

data.json

@@ -380,16 +380,6 @@
     "username_claimed": "blue",
     "username_unclaimed": "noonewouldeverusethis7"
   },
-  "Duolingo": {
-    "errorType": "response_url",
-    "errorUrl": "https://www.duolingo.com/errors/404.html",
-    "rank": 538,
-    "regexCheck": "^[a-zA-Z0-9_-]{3,16}$",
-    "url": "https://www.duolingo.com/{}",
-    "urlMain": "https://www.duolingo.com/",
-    "username_claimed": "blue",
-    "username_unclaimed": "noonewoulduse"
-  },
   "Ebay": {
     "errorMsg": "The User ID you entered was not found",
     "errorType": "message",

removed_sites.md

@@ -6,9 +6,26 @@ They are listed here in the hope that things may change in the future
 so they may be re-included.
 
 
+## Duolingo
+
+Usernames that don't exist are detected.
+
+```
+  "Duolingo": {
+    "errorType": "response_url",
+    "errorUrl": "https://www.duolingo.com/errors/404.html",
+    "rank": 538,
+    "regexCheck": "^[a-zA-Z0-9_-]{3,16}$",
+    "url": "https://www.duolingo.com/{}",
+    "urlMain": "https://www.duolingo.com/",
+    "username_claimed": "blue",
+    "username_unclaimed": "noonewoulduse"
+  },
+```
+
 ## EVE Online
 
-Usernames that exists are not detected.
+Usernames that exist are not detected.
 
 ```
   "EVE Online": {
@@ -24,7 +41,7 @@ Usernames that exists are not detected.
 
 ## AngelList
 
-Username that exists is not detected.
+Usernames that exist are not detected.
 
 ```
   "AngelList": {
@@ -39,7 +56,7 @@ Username that exists is not detected.
 
 ## Codepen
 
-Username that exists is not detected.
+Usernames that exist are not detected.
 
 ```
   "Codepen": {