Add some maintenance documentation

docs/Maintenance.md

@@ -0,0 +1,19 @@
+# Maintenance
+
+## How to upgrade
+
+There are different things that can be upgraded:
+
+- The python package dependencies (normal dependencies and dev dependencies)
+  -- Check outdated Python packages: `inv show-outdated` (check Python section in output)
+  -- `poetry update` will update packages according to their version range in `pyproject.toml`
+  -- Other upgrades (e.g. major versions) must be upgraded by modifying the version range in `pyproject.toml` before calling `poetry update`
+- Javascript dependencies
+  -- Check outdated Javascript packages: `inv show-outdated` (check Javascript section in output)
+  -- `npm update` will update packages according to their version range in `package.json`
+  -- Other upgrades (e.g. major versions) must be upgraded by modifying the version range in `packages.json` before calling `npm update`
+  -- After an upgrade make sure the files in `static/vendor` still link to the correct files in `node_modules`1
+- Python and Poetry in `Dockerfile` that builds the container where RADIS runs in
+- Dependent services in `docker-compose.base.yml`, like PostgreSQL or Vespa database
+- Gitpod development container dependencies in `.gitpod.Dockerfile`
+- Github Codespaces development container dependencies in `.devcontainer/devcontainer.json` and `.devcontainer/Dockerfile`