Merge pull request #117 from squat/maintainers

MAINTAINERS.md: propose @leonnicolas as maintainer

MAINTAINERS.md

@@ -0,0 +1,6 @@
+# Core Maintainers of This Repository
+
+| Name               | GitHub                                         |
+|--------------------|------------------------------------------------|
+| Lucas Servén Marín | [@squat](https://github.com/squat)             |
+| Leon Löchner       | [@leonnicolas](https://github.com/leonnicolas) |