Fix some typos, broken links and other issues in extension docs

chrome/common/extensions/docs/templates/intros/declarativeWebRequest.html

 <h2 id="notes">Notes</h2>
 
 <p>
 Use the <code>chrome.declarativeWebRequest</code> module to intercept, block, or
 modify requests in-flight. It is significantly faster than the <a
   href="webRequest.html"><code>chrome.webRequest</code> API</a> because you can
 register rules that are evaluated in the browser rather than the
 JavaScript engine which reduces roundtrip latencies and allows very high
 efficiency.
 </p>
 
 <h2 id="manifest">Manifest</h2>
 
 <p>
 You must declare the "declarativeWebRequest" permission in the
 <a href="manifest.html">extension manifest</a> to use this API,
-along with <a href="manifest.html#permissions">host permissions</a> for any
+along with <a href="declare_permissions.html">host permissions</a> for any
 hosts whose network requests you want to access.
 </p>
 
 <pre>{
   "name": "My extension",
   ...
 <b>  "permissions": [
     "declarativeWebRequest",
     "*://*.google.com"
   ]</b>,
@@ skipping 207 matching lines @@
 chrome.declarativeWebRequest.onRequest.addRules([rule1, rule2]);
 </pre>
 
 <p>
 It is important to recognize that the <code>IgnoreRules</code> action is not
 persisted across <a href="#evaluation">request stages</a>. All conditions of
 all rules are evaluated at each stage of a web request. If an
 <code>IgnoreRules</code> action is executed, it applies only to other actions
 that are executed for the same web request in the same stage.
 </p>