Add docs-config-filter command and fix mkdoc.yml duplication.

Author: bircher

Diff for: lib/Drush/Commands/core/DocsCommands.php

@@ -67,6 +67,17 @@ public function configExport() {
     self::printFile(DRUSH_BASE_PATH. '/docs/config-exporting.md');
   }
 
+  /**
+   * Drupal configuration filter instructions for changing yml files during import/export.
+   *
+   * @command docs-config-filter
+   * @hidden
+   * @topic
+   */
+  public function configFilter() {
+    self::printFile(DRUSH_BASE_PATH. '/docs/config-filter.md');
+  }
+
   /**
    * Site aliases overview on creating your own aliases for commonly used Drupal sites with examples from example.aliases.drushrc.php.
    *

Diff for: mkdocs.yml

@@ -22,8 +22,4 @@ pages:
   - Bootstrap: bootstrap.md
   - Context system: context.md
   - Filtering Drupal configuration: config-filter.md
-theme: readthedocs
-site_author: ""
-repo_url: https://github.com/drush-ops/drush
-include_search: true
 #use_directory_urls: false