add issue template to create session proposals

Author: christian-bromann

.github/ISSUE_TEMPLATE/session-proposal.md

@@ -0,0 +1,31 @@
+---
+name: Code&Learn Session Proposal
+about: Submit a session proposal for the Code&Learn event
+title: 'Session Topic: '
+labels: Session Proposal
+assignees: christian-bromann, evahowe, jorydotcom, keywordnew
+
+---
+
+<!--
+Thank you! You are submitting a proposal for a session at the Code&Learn, Montreal 2019!
+
+Please include as much detail as you are able to at this moment. Don't worry, it doesn't have to be complete.
+
+Please feel free to link to any other issue, PR, or resource that could be relevant. This will help
+us to find the right faciliator from the project.
+-->
+
+**Topic of the session**
+
+
+**Project**
+<!--
+You can find a list of participating projects here: https://github.com/openjs-foundation/code-and-learn#participating-projects. Please label the issue with the appropiate project label.
+-->
+
+
+**Describe the session**
+
+
+**Additional context (optional)**