Update issue templates

Create templates for bug reports, clarification requests and feature/improvement requests.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,27 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+title: "[IMPROVEMENT]"
+labels: ''
+assignees: ''
+
+---
+
+Thanks for helping us improve this project!
+
+**Before you create this issue**
+Please make sure you are using the latest updated code and libraries: see https://github.com/ageron/handson-ml2/blob/master/INSTALL.md#update-this-project-and-its-libraries
+
+Also please make sure to read the FAQ (https://github.com/ageron/handson-ml2#faq) and search for existing issues (both open and closed), as your question may already have been answered: https://github.com/ageron/handson-ml2/issues
+
+**Is your feature request related to a problem? Please describe.**
+Please indicate the notebook name and cell number where the problem occurs (or the chapter and page number in the book), and provide a clear and concise description of what the problem is. Ex.  In chapter 1, cells 200-220, I think the code could be clearer [...]
+
+**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.