fix tutorial issue template

apparently there is a 200 characters length limit on the `about` field

.github/ISSUE_TEMPLATE/tutorial.md

@@ -1,23 +1,29 @@
 ---
 name: Tutorial request
-about: Suggest a topic for a new tutorial and propose where to put it in the [planned outline](https://github.com/NixOS/nix.dev/issues/572). Please check [existing tutorial requests](https://github.com/NixOS/nix.dev/issues?q=is%3Aopen+is%3Aissue+label%3Atutorial) before submitting. Check our [guide on writing new tutorials](https://nix.dev/contributing/documentation/writing-a-tutorial) if you want to help.
+about: Suggest a topic for a new tutorial and propose where to put it in the [planned outline](https://github.com/NixOS/nix.dev/issues/572).
 labels: tutorial
 ---
 
 **Learning goals**
 <!-- Which skill do you want to acquire? -->
 
+
 **Prerequisites**
 <!-- What do you already know how to do? -->
 
+
 **Outline**
 <!-- Which steps do you envision the tutorial to cover? -->
 
+
 **Prior art**
 <!-- Are there existing materials that are related, similar, or almost but not quite what you need? -->
 
+
 **Willing to help?**
 <!-- Are you willing to help write the tutorial? -->
+<!--  Check our guide on writing new tutorials: https://nix.dev/contributing/documentation/writing-a-tutorial -->
+
 
 **Priorities**