[X] The solution proposed fixes the issues described.
Performed by visual inspection: I have opened the README and checked that the new section is there, is in its correct location, and it's accurate. The issue is with the README. There is no good, automated way to check that it is correct.
[X] Implementation is documented. Details:
The change is to the documentation.
[X] Change history is clear.
[X] Commit messages are clear.
[X] Changelogs are updated.
[X] Examples are updated. Details:
No updates needed.
[X] Required version bumps are evaluated. Details:
Bump not needed (bug fix).
Document, in the README, the format of the variables DB file, as prescribed in the solution proposed for #143.