Add: mi_NZ template

Author: LordAro

.github/ISSUE_TEMPLATE/translator_mi_NZ.md

@@ -0,0 +1,19 @@
+---
+name: Translator access to Maori (New Zealand) (mi_NZ)
+about: Do you want access for translating into Maori (New Zealand)?
+title: "[mi_NZ] Translator access request"
+labels: request_access
+---
+
+<!-- translator: mi_NZ -->
+<!-- Please do not edit the header of this template. -->
+
+Hi,
+
+I would like to ask for access to help translating OpenTTD and its subprojects into **Maori (New Zealand)**.
+
+The **Maori (New Zealand)** language is well known to me, and I promise to cooperate with my fellow translators to give the end-users the best experience possible.
+
+<!-- Please do not edit the above message. Do feel free to add a personal note after this line. -->
+
+Thank you,