Refactor devfile docs
What does this MR do and why?
Refactor devfile docs. Add details about the restrictions on the devfile that we impose at GitLab for Remote Development in https://gitlab.com/gitlab-org/gitlab/-/blob/5848f31b815919f481ca1a9e1c6b91a694608f98/ee/lib/remote_development/workspaces/create/pre_flatten_devfile_validator.rb and https://gitlab.com/gitlab-org/gitlab/-/blob/5848f31b815919f481ca1a9e1c6b91a694608f98/ee/lib/remote_development/workspaces/create/post_flatten_devfile_validator.rb
MR acceptance checklist
Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.
Edited by Vishal Tak