Docs: debugger protocol link fix.

chrome/common/extensions/docs/templates/json/chrome_sidenav.json

 [
   {
     "title": "Devtools",
     "items": [
       {
         "title": "Learn Basics",
         "href": "/devtools",
         "items": [
           {
             "title": "Overview",
@@ skipping 152 matching lines @@
               {
                 "title": "Showcase Debugging Protocol Clients",
                 "href": "/devtools/docs/debugging-clients"
               },
               {
                 "title": "Version 1.1 (Stable)",
                 "href": "/devtools/docs/protocol/1.1/index"
               },
               {
                 "title": "Tip-of-tree (Unstable)",
-                "href": "/devtools/docs/protocol/tot/index"
+                "href": "https://chromedevtools.github.io/debugger-protocol-viewer/"
               },
               {
                 "title": "Version 1.0",
                 "href": "/devtools/docs/protocol/1.0/index"
               },
               {
                 "title": "Version .1",
                 "href": "/devtools/docs/protocol/0.1/index"
               }
             ]
@@ skipping 873 matching lines @@
                 "title": "Articles",
                 "href": "/webstore/articles"
               }
             ]
           }
         ]
       }
     ]
   }
 ]