Add default MR template, add Documentation and Feature issue template.

.gitlab/issue_templates/Documentation.md

+## Faulty documentation
+
+(Present here what you think is missing/not up to date in the documentation)
+
+[link to the faulty documentation if possible]($PATH_TO_DOC)
+
+## Possible Fixes
+
+(If you can, suggest a possible fix)
+
+
+/label ~Add::Documentation 📚

.gitlab/issue_templates/Feature.md

+## Description
+
+(Explain the problem to be solved)
+
+## Proposal
+
+(Describe the solution you'd like - A clear and concise description of what you want to happen)
+
+## Additional context
+
+(If you want, add any other context or screenshots about the feature request)
+
+
+/label ~Add::Feature

.gitlab/merge_request_templates/Default.md

+## Context
+
+(Summarize the problem you are facing and the solution you propose to resolve the issue)
+
+(If possible add link to a gitlab issue #...)
+
+(Describe the issue - you can paste any logs or/screenshots, the link to the line of code that might be responsible for the problem)
+
+(In the case of feature addition, describe the context arround the need of this addition)
+
+## Modified files
+
+(Summarize the changes you made for each modified file - example:
+- `DeepNet.hpp` and `DeepNet.cpp`, add several learning methods;
+- `learn.cpp`, to include the learning functions inside the main function;
+- `test_conv.cpp`, to correct the new syntax in the tests; )
+
+## Detailed major modifications
+
+(Explain the non-trivial changes you made in the modified files)
+
+(Specify if you made an important technical decision which should be added to the wiki https://gitlab.eclipse.org/groups/eclipse/aidge/-/wikis/home or the documentation)
+
+
+## TODO
+
+(List the changes that need to be done to track the progress of the MR, you need to update the list when committing !)
+
+- [ ] NOT DONE
+- [X] DONE
+- [ ] TO DO