fix typo in basic_concepts.md (#17285)

docs/sources/guides/basic_concepts.md

@@ -66,7 +66,7 @@ There are a wide variety of styling and formatting options that each Panel expos
 
 Panels can be dragged and dropped and rearranged on the Dashboard. They can also be resized.
 
-There are currently four Panel types: [Graph](/reference/graph/), [Singlestat](/reference/singlestat/), [Dashlist](/reference/dashlist/), [Table](/reference/table_panel/),and [Text](/reference/text/).
+There are currently five Panel types: [Graph](/reference/graph/), [Singlestat](/reference/singlestat/), [Dashlist](/reference/dashlist/), [Table](/reference/table_panel/), and [Text](/reference/text/).
 
 Panels like the [Graph](/reference/graph/) panel allow you to graph as many metrics and series as you want. Other panels like [Singlestat](/reference/singlestat/) require a reduction of a single query into a single number. [Dashlist](/reference/dashlist/) and [Text](/reference/text/) are special panels that do not connect to any Data Source.