Added Dot at the end of line (#28233)

Hi - Added Dot at the end of line to make it consistent.

Thanks,
Ashish

docs/sources/variables/variable-types/global-variables.md

@@ -83,5 +83,5 @@ This is used in several places, including:
 
 - The WHERE clause for the InfluxDB data source. Grafana adds it automatically to InfluxDB queries when in Query Editor mode. You can add it manually in Text Editor mode: `WHERE $timeFilter`.
 - Log Analytics queries in the Azure Monitor data source.
-- SQL queries in MySQL, Postgres, and MSSQL
+- SQL queries in MySQL, Postgres, and MSSQL.
 - The `$__timeFilter` variable is used in the MySQL data source.