Issue/PR templates (#180)

* create .github directory to hold issue/PR templates and contributing guide

* update link to Contributing guide in Readme
diff --git a/README.md b/README.md
index 4d2efaf..0e1fe06 100644
--- a/README.md
+++ b/README.md
@@ -131,7 +131,7 @@
 
 ## Contributing
 
-See the [contributing guide](./CONTRIBUTING.md).
+See the [contributing guide](./.github/CONTRIBUTING.md).
 
 ## Help and feedback