[Doc] Fix links from gitlab README.md to sphinx documentation

Fix links from gitlab README.md to sphinx documentation

Developer guide links to latest version.

1. Feature description was added to the changelog
2. Tests covering your feature were added?
3. Any new feature or behaviour change was documented?
4. API-breaking changes documented here

requested review from @FZill

assigned to @TobiasMeisel

added workflowplease review label

added Documentation (only) label

added 3 commits

• 20b200e5 - [Doc] Fix links from gitlab README.md to sphinx documentation
• f6ccbe60 - [Doc] Fix release notes links to previous release (0.4.0)
• 896f4409 - [Doc] Fix other links from gitlab to sphinx

Compare with previous version

enabled an automatic merge when all merge checks for 896f4409 pass

mentioned in commit 55882677

merged

changed milestone to %0.5.0 Release