Docs: integration tests for using sqllite (#49455)

* Update developer-guide.md

* prettier formatting

contribute/developer-guide.md

@@ -136,17 +136,23 @@ Running the backend tests on Windows currently needs some tweaking, so use the b
 go run build.go test
 ```
 
-### Run PostgreSQL and MySQL integration tests
+### Run SQLLite, PostgreSQL and MySQL integration tests
+
+By default grafana runs SQLite, to run test with SQLite
+
+```bash
+go test -covermode=atomic -tags=integration ./pkg/...
+```
 
 To run PostgreSQL and MySQL integration tests locally, you need to start the docker blocks for MySQL and/or PostgreSQL test data sources by running `make devenv sources=mysql_tests,postgres_tests`. When your test data sources are running, you can execute integration tests by running:
 
-```
+```bash
 GRAFANA_TEST_DB=mysql go test -covermode=atomic -tags=integration ./pkg/...
 ```
 
 and/or
 
-```
+```bash
 GRAFANA_TEST_DB=postgres go test -covermode=atomic -tags=integration ./pkg/...
 ```