Update manifest.md

Author: Nkrb

powerapps-docs/developer/component-framework/manifest-schema-reference/manifest.md

@@ -25,7 +25,7 @@ Model-driven apps and canvas apps (public preview)
 
 |Element|Description|Occurrences|Available for|
 |--|--|--|-------|
-|[control](control.md)|[!INCLUDE [control-description](includes/control-description.md)]|1 or more|Model-driven apps and canvas apps (public preview) |
+|[control](control.md)|[!INCLUDE [control-description](includes/control-description.md)]|1|Model-driven apps and canvas apps (public preview) |
 |[type-group](type-group.md)|[!INCLUDE [type-group-description](includes/type-group-description.md)]|0 or more|Model-driven apps and canvas apps (public preview) |
 |[property](property.md)|[!INCLUDE [property-description](includes/property-description.md)]|0 or more|Model-driven apps and canvas apps (public preview) |
 |[data-set](data-set.md)|[!INCLUDE [data-set-description](includes/data-set-description.md)]|0 or more|Model-driven apps|