Fix some links to "Adding New Classes" in docs

Summary: Fixes T9483. This bookname is `phabcontrib`, not `contributor`.

Test Plan: `grep` / clicked these links.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T9483

Differential Revision: https://secure.phabricator.com/D14195

src/docs/contributor/internationalization.diviner

@@ -22,7 +22,8 @@ introduce a new locale, like "German" or "Klingon".
 Once you've created a locale, applications can add translations for that
 locale.
 
-For instructions on adding new classes, see @{article:Adding New Classes}.
+For instructions on adding new classes, see
+@{article@phabcontrib:Adding New Classes}.
 
 
 Adding Translations to Locale
@@ -36,7 +37,8 @@ Translations are separated from locales so that third-party applications can
 provide translations into different locales without needing to define those
 locales themselves.
 
-For instructions on adding new classes, see @{article:Adding New Classes}.
+For instructions on adding new classes, see
+@{article@phabcontrib:Adding New Classes}.
 
 
 Writing Translatable Code
@@ -375,4 +377,5 @@ Next Steps
 
 Continue by:
 
-  - adding a new locale or translation file with @{article:Adding New Classes}.
+  - adding a new locale or translation file with
+    @{article@phabcontrib:Adding New Classes}.

src/docs/user/configuration/custom_fields.diviner

@@ -213,5 +213,5 @@ integrations, see the base class for your application and
 Continue by:
 
   - learning more about extending Phabricator with custom code in
-    @{article@contributor:Adding New Classes};
+    @{article@phabcontrib:Adding New Classes};
   - or returning to the @{article: Configuration Guide}.

src/docs/user/configuration/managing_daemons.diviner

@@ -109,7 +109,7 @@ This daemon will daemonize and run normally.
     just those started with `phd start`. If you're writing a restart script,
     have it launch any custom daemons explicitly after `phd restart`.
   - You can write your own daemons and manage them with `phd` by extending
-    @{class:PhabricatorDaemon}. See @{article@contributor:Adding New Classes}.
+    @{class:PhabricatorDaemon}. See @{article@phabcontrib:Adding New Classes}.
   - See @{article:Diffusion User Guide} for details about tuning the repository
     daemon.
 
@@ -137,4 +137,4 @@ Continue by:
 
   - learning about the repository daemon with @{article:Diffusion User Guide};
     or
-  - writing your own daemons with @{article@contributor:Adding New Classes}.
+  - writing your own daemons with @{article@phabcontrib:Adding New Classes}.

src/docs/user/userguide/arcanist_lint_unit.diviner

@@ -38,7 +38,7 @@ make this work, you need to do three things:
 
 If you haven't created a library for the class to live in yet, you need to do
 that first. Follow the instructions in
-@{article@contributor:Adding New Classes}, then make the library loadable by
+@{article@phabcontrib:Adding New Classes}, then make the library loadable by
 adding it to your `.arcconfig` like this:
 
   {

src/docs/user/userguide/arcanist_new_project.diviner

@@ -47,7 +47,7 @@ Other options include:
 
   - **load**: list of additional Phutil libraries to load at startup.
     See below for details about path resolution, or see
-    @{article@contributor:Adding New Classes} for a general introduction to
+    @{article@phabcontrib:Adding New Classes} for a general introduction to
     libphutil libraries.
   - **https.cabundle**: specifies the path to an alternate certificate bundle
     for use when making HTTPS connections.

src/docs/user/userguide/diffusion_symbols.diviner

@@ -88,7 +88,7 @@ You can configure some more options by going to {nav Diffusion > (Select
 
 == External Symbols ==
 
-By @{article:Adding New Classes}, you can teach Phabricator
+By @{article@phabcontrib:Adding New Classes}, you can teach Phabricator
 about symbols from the outside world.
 Extend @{class:DiffusionExternalSymbolsSource}; Once loaded, your new
 implementation will be used any time a symbol is queried.

src/docs/user/userguide/events.diviner

@@ -21,7 +21,7 @@ To install event listeners in Phabricator, follow these steps:
 
   - Write a listener class which extends @{class@libphutil:PhutilEventListener}.
   - Add it to a libphutil library, or create a new library (for instructions,
-    see @{article@contributor:Adding New Classes}.
+    see @{article@phabcontrib:Adding New Classes}.
   - Configure Phabricator to load the library by adding it to `load-libraries`
     in the Phabricator config.
   - Configure Phabricator to install the event listener by adding the class
@@ -38,7 +38,7 @@ To install event listeners in Arcanist, follow these steps:
 
   - Write a listener class which extends @{class@libphutil:PhutilEventListener}.
   - Add it to a libphutil library, or create a new library (for instructions,
-    see @{article@contributor:Adding New Classes}.
+    see @{article@phabcontrib:Adding New Classes}.
   - Configure Phabricator to load the library by adding it to `load`
     in the Arcanist config (e.g., `.arcconfig`, or user/global config).
   - Configure Arcanist to install the event listener by adding the class