Update issue templates

added new reference template

.github/ISSUE_TEMPLATE/new-reference.md

@@ -0,0 +1,19 @@
+---
+name: New reference
+about: Add new reference to the shared bibliography
+title: "[NEW REFERENCE]: <title of the reference>"
+labels: to read
+assignees: alexpron
+
+---
+
+Thank you for taking the time to create an issue to add a reference to the shared bibliography
+
+###  Required field
+
++ doi: < doi of the reference to add>
+
+if a doi is not available or if you dont wan to bother filling the doi please copy paste as much information as you can to identify the reference in the hereunder section
+
+###  Unstructured information
+You can paste there all the information about the publication in a unstructured way (e.g. a tweet) so that reference can be identified