Merge pull request #798 from HeidiSteen/heidist-proj3

[azure search] Ported content for PR clean up

Author: v-dirichards

articles/search/.openpublishing.redirection.search.json

@@ -1,5 +1,10 @@
 {
     "redirections": [
+        {
+            "source_path_from_root": "/articles/search/index-projections-concept-intro.md",
+            "redirect_url": "/azure/search/search-how-to-define-index-projections",
+            "redirect_document_id": true
+        },
         {
             "source_path_from_root": "/articles/search/tutorial-javascript-overview.md",
             "redirect_url": "/azure/search/tutorial-csharp-overview",