Add description templates

Description

Gitlab offers templates definition for issue reporting and merge requests. Maybe we should start with issue templates?

Proposal

We can add some templates - let's say for bug report and feature proposal to begin with. These are simple *.md files placed in a proper directory in repository.

Links / references

docker description templates Let's first focus on MR docker!5 (merged), then we will just copy these files.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information