DOCSP-47018 Authentication Reorg (mongodb#502)

* DOCSP-47018 Authentication Reorg

* edits

* edit

* add landing page

* ref check

* landing page refs

* fix connect ref

* edit

* vale get rid of should

* 1/2 RR Review

* rest of comments

* fix toc

* ad landing page

* edit

Author: lindseymoore

snooty.toml

@@ -4,7 +4,9 @@ toc_landing_pages = [
     "/connect",
     "/crud",
     "/monitoring-and-logging",
-    "/security"
+    "/security",
+    "/security/authentication",
+    "/connect/specify-connection-options"
 ]
 
 intersphinx = [