Add issue template for Tensorflow for Microcontrollers.

This template:
 * tags the micro team on github
 * adds the comp:micro label

PiperOrigin-RevId: 285297116
Change-Id: I04304cf1ca1702afc2adf63a66b14c622359872d

.github/ISSUE_TEMPLATE/70-tflite-micro-issue.md

@@ -0,0 +1,19 @@
+---
+name: TensorFlow Lite for Microcontrollers Issue
+about: Use this template for reporting issues with TensorFlow Lite for microcontrollers
+labels: 'comp:micro'
+
+---
+
+@tensorflow/micro
+
+**System information**
+- Host OS Platform and Distribution (e.g., Linux Ubuntu 16.04):
+- TensorFlow installed from (source or binary):
+- Tensorflow version (commit SHA if source):
+- Target platform (e.g. Arm Mbed OS, Arduino Nano 33 etc.):
+
+**Describe the problem**
+
+**Please provide the exact sequence of commands/steps when you ran into the problem**
+