Merge branch 'add-templates' into 'master'

Add templates

Closes #15

See merge request qtg/grey-hack!20

.gitlab/issue_templates/Bug.md

+# Files affected
+*Which file(s) is(are) affected*
+- *File*
+
+# Steps to reproduce
+*A step-by-step explanation of the way to follow and the configuration to have to reproduce the bug*
+- *Step 1*
+- *Step 2*
+- *…*
+
+# Expected behaviour
+*Explain what should happen*
+
+# Actual behaviour
+*Describe precisely what is currently happening, with pictures or error messages if relevant*
+
+# Possible fixes
+*If you have a clue, explain which part of the code may need fixing, and how (don't forget to use code formatting for the code!)*
+```
+print("Hello World!")
+```
+
+/label ~bug

.gitlab/issue_templates/Feature request.md

+# Which part would be affected
+*Specify which functionnality would be changed, and if you know it, which file(s) or part of file(s)*
+
+# Description of the feature
+*What would it do?*
+
+# How would it enhance the experience?
+*Describe the  motivation for the change: how would the experience be better with this change?*
+
+# Checks to do
+*File or features to check would not be impacted by the changes*
+
+/label ~enhancement
+/label ~suggestion

.gitlab/merge_request_templates/Bug fix.md

+# Bug
+*Link to issue #number and short description of the bug*
+
+# Changes
+*Give a quick summary of the changes you have done and why*
+
+# Checks
+I have verifed the following:
+- [ ] Fixes the issue
+- [ ] Does not introduces an obvious bug or vulnerability
+- [ ] Code has been duely tested
+- [ ] Follows the coding style