DOC-266 add the dang period

Author: markzegarelli

src/connections/destinations/catalog/actions-slack/index.md

@@ -34,7 +34,7 @@ Slack (Actions) provides the following benefits over the classic Slack destinati
 
 ## Important differences from the classic Slack destination
 
-- The classic Slack destination formats messages using the handlebars syntax. Slack (Actions) follows [Slack's  formatting syntax](https://api.slack.com/reference/surfaces/formatting){:target="_blank"}
+- The classic Slack destination formats messages using the handlebars syntax. Slack (Actions) follows [Slack's  formatting syntax](https://api.slack.com/reference/surfaces/formatting){:target="_blank"}.
 
 ## Available Slack actions