[docs][ci skip] Adding issue template

ISSUE_TEMPLATE.md

@@ -0,0 +1,37 @@
+Hi!
+
+I was checking out the awesome libpostal, and saw something that could be improved.
+
+---
+#### My country is
+<!-- If you were Carmen Sandiego, where in the world would you be? -->
+
+---
+#### Here's how I'm using libpostal
+<!-- Always interested to know how people use the library! What are you working on? Which orgnization? What's your use case? -->
+
+---
+#### Here's what I did
+<!-- the input you used in the case of results issues, your system configuration for compilation issues/bugs, etc. -->
+
+---
+#### Here's what I got
+<!-- the output from the parser or make, etc. Try to paste the exact result/output. -->
+
+---
+#### Here's what I was expecting
+<!-- what should the correct parse/output have been? Try to be specific. -->
+
+---
+#### For parsing issues, please check all that apply
+
+- [ ] Does the input address exist in [OpenStreetMap](https://openstreetmap.org)?
+- [ ] Do all the toponyms exist in OSM (city, state, region names, etc.)?
+- [ ] If the address uses a rare/uncommon format, does changing the order of the fields yield the correct result?
+- [ ] If the address does not contain city, region, etc., does adding those fields to the input improve the result?
+- [ ] If the address contains apartment/floor/sub-building information or uncommon formatting, does removing that help? Is there any minimum form of the address that gets the right parse?
+
+---
+#### Here's what I think could be improved
+<!-- suggestions for what could be done differently -->
+