Update issue templates (#500)

* Update issue templates

* Update bug_report.md

Author: wti806

.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,50 @@
+---
+name: Bug report
+about: Create a report to help us improve
+
+---
+
+<!-- Step 1 [READ THIS] -->
+<!--
+Are you in the right place?
+  * For issues or feature requests related to __the code in this repository__
+    file a Github issue.
+    * If this is a __feature request__ make sure the issue title starts with "FR:".
+  * For general technical questions, post a question on [StackOverflow](http://stackoverflow.com/)
+    with the firebase-authentication tag.
+  * For general Firebase discussion, use the [firebase-talk](https://groups.google.com/forum/#!forum/firebase-talk)
+    google group.
+  * For help troubleshooting your application that does not fall under one
+    of the above categories, reach out to the personalized
+    [Firebase support channel](https://firebase.google.com/support/).
+-->
+
+<!-- Step 2 -->
+
+### [REQUIRED] Describe your environment
+
+  * Operating System version: _____
+  * Browser version: _____
+  * Firebase UI version: _____
+  * Firebase SDK version: _____
+
+<!-- Step 3 -->
+
+### [REQUIRED] Describe the problem
+
+#### Steps to reproduce:
+<!--
+  What happened? How can we make the problem occur?
+  This could be a description, log/console output, etc.
+-->
+#### Relevant Code:
+
+<!--
+  Reproduce the issue on StackBlitz and provide your forked URL
+  or give us some sample code below
+-->
+https://stackblitz.com/fork/firebase-issue-sandbox
+
+```javascript
+// TODO(you): code here to reproduce the problem
+```

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,17 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+
+---
+
+**Is your feature request related to a problem? Please describe.**
+A clear and concise description of what the problem is. Ex. I'm always frustrated when [...]
+
+**Describe the solution you'd like**
+A clear and concise description of what you want to happen.
+
+**Describe alternatives you've considered**
+A clear and concise description of any alternative solutions or features you've considered.
+
+**Additional context**
+Add any other context or screenshots about the feature request here.