Don't watch the build docs dir (#484)

Before 40415a3 the plugin was creating a new temporary directory on every reload so built artifacts weren't marked as changed. After the update, the same temporary directory is used. This caused built artifacts to trigger a file change event.

This fix unwatches the build docs dir so those changes don't fire rebuild events. Now only file changes in the source directory should trigger rebuilds as expected.

mkdocs_simple_plugin/plugin.py

@@ -329,7 +329,8 @@ def on_serve(self, server, *, config, builder):
         # watch the original docs/ directory
         if os.path.exists(self.orig_docs_dir):
             server.watch(self.orig_docs_dir)
-        server.watch(self.config["build_docs_dir"])
+        # don't watch the build directory
+        server.unwatch(self.config["build_docs_dir"])
 
         # watch all the doc files
         for path in self.paths: