Add documentation for the chrome.sockets API and manifest key.

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

Index: chrome/common/extensions/docs/templates/json/manifest.json
diff --git a/chrome/common/extensions/docs/templates/json/manifest.json b/chrome/common/extensions/docs/templates/json/manifest.json
index 4564d9ad71d824cc0ed63dedc14d13185df29017..194cf0e122fbdacf953b27f528d65e70afcef2df 100644
--- a/chrome/common/extensions/docs/templates/json/manifest.json
+++ b/chrome/common/extensions/docs/templates/json/manifest.json
@@ -139,6 +139,12 @@
     "documentation": "manifest/name.html#short_name",
     "example": "Short Name"
   },
+  "sockets": {
+    "documentation": "manifest/sockets.html",
+    "example": {
+      "tcp": { "connect": "*" }, "udp": { "send": "*" }
+    }
+  },
   "storage": {
     "documentation": "manifest/storage.html",
     "example": {