Update .github/CODEOWNERS

Co-authored-by: Mikael Simberg <[email protected]>

Author: rsarm

.github/CODEOWNERS

@@ -1,5 +1,5 @@
 * @bcumming @msimberg @RMeli
-docs/services/jupyterlab @rsarm
+docs/services/jupyterlab.md @rsarm
 docs/services/firecrest @jpdorsch @ekouts
 docs/software/communication @Madeeks @msimberg
 docs/software/devtools/linaro @jgphpc