Resolve "TNC improvements"

Closes #74 (closed)

docs/managed-nmaas/introduction.md

-# Introduction to Managed NMaaS
+# Introduction to Managed nmaas Instances
 
-Work in progress. Content will be provided soon!
+The GEANT project offers two managed instances of nmaas, dedicated to specific use-cases:
+
+- The nmaas Virtual NOC managed instance hosted at [https://nmaas.eu](https://nmaas.eu)
+- The nmaas Virtual Lab managed instance hosted at [https://vlab.dev.nmaas.eu](https://vlab.dev.nmaas.eu)
+
+## The Virtual NOC Managed Instance
+
+The [nmaas Virtual NOC managed instance](https://nmaas.eu) is aimed at NRENs or NREN end-institutions and provides an effortless way of getting started with basic network monitoring and management. Potential users can request on-boarding into the nmaas Virtual NOC managed instance by filling out the `New domain request` form available on [https://nmaas.eu/about](https://nmaas.eu/about).
+
+## The Virtual Lab Managed Instance
+
+The [nmaas Virtual Lab managed instance](https://vlab.dev.nmaas.eu) acts as a demo environment for testing the newly developed features enabling the Virtual Lab use-case. It can support small scale exercises with around 20 students. In cases of bigger courses, institutions are encouraged to deploy an nmaas instance locally, on their own infrastructure. Interested users in either evaluating nmaas Virtual Lab on the managed instance or deploying it on their own infrastructure can get in touch with the nmaas team using one of the [contact methods](../contact.md).
\ No newline at end of file