Explain how to update tool_status.tsv

As I understand `tool_status.tsv` is only created once, and then the `to keep` needs to be added.
How to add more rows ?
@scorreard @bebatut ?

Start by tracing how tool_status.tsv is initially created and where the existing “to keep” entries are maintained. Confirm the procedure for adding more rows, then document it with a clear example; the work is done when a newcomer can update the file without further clarification.

Written by the indexing model from the issue text.