Create feature_request.md

Author: betaBison

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,15 @@
+---
+name: Feature request
+about: Propose a new feature
+title: ''
+labels: enhancement
+assignees: ''
+
+---
+
+**Describe the proposed feature**
+Explain in detail the intended feature, its purpose and how it would work.
+Keep the scope as narrow as possible, which will make it easier to implement.
+
+**Motivate the proposed feature**
+Help us understand why the proposed feature would help you and/or make `gnss_lib_py` easier to use.