docs: minor updates to to new API doc

Fix a filename and add a couple missing words.
Signed-off-by: NJonathon Jongsma <jjongsma@redhat.com>
Message-Id: <20190705192829.1223-1-jjongsma@redhat.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

docs/api_extension.html.in

@@ -229,8 +229,8 @@
     <h3><a name='rpcclient'>Implement the RPC client</a></h3>
 
     <p>
-      Implementing the uses the rpcgen generated .h files.  The remote
-      method calls go in:
+      Implementing the RPC client uses the rpcgen generated .h files.
+      The remote method calls go in:
     </p>
 
     <p><code>src/remote/remote_driver.c</code></p>
@@ -256,7 +256,7 @@
       The server side dispatchers are implemented in:
     </p>
 
-    <p><code>src/remote/daemon_dispatch.c</code></p>
+    <p><code>src/remote/remote_daemon_dispatch.c</code></p>
 
     <p>Again, this step uses the .h files generated by make rpcgen.</p>