docs: add debug info (#55)

Author: vaeng

docs/TESTS.md

@@ -14,6 +14,11 @@ This command initializes SQLite with an empty database, runs the tests specified
 
 The test results will be displayed in the console as a table, showing the description of each test, its status (e.g., "pass"), and a message if the status is "fail."
 
+## Debugging
+
+You can use `SELECT` statements for debugging.
+The output will be forwarded to `user_output.md` and shown in the web-editor if tests fail.
+
 ## Execution Details
 
 The test file (`${slug}_test.sql`) is a pretty complex script.

exercises/shared/.docs/tests.md

@@ -6,4 +6,7 @@ Navigate to the directory containing the appropriate `${slug}-test.sql` file, wh
 sqlite3 -bail < ${slug}-test.sql
 ```
 
+You can use `SELECT` statements for debugging.
+The output will be forwarded to `user_output.md` and shown in the web-editor if tests fail.
+
 You can find more information in the [sqlite track docs about testing](https://exercism.org/docs/tracks/sqlite/tests).