The linkchecker script is not working the same way as the `scripts/lsync.sh`.
- The path must start with '/docs'. This is not implied in any way.
- The language can be deduced if user provides a full path to a markdown
file, e.g. `content/en/docs/concepts/security/controlling-access.md`.
- The path parameter could use a positional argument for ease of use.
This PR improves the user experience for the tool.