export / import rules individually

[kuzn123]

It is advisable to add the export / import function not only for all rules at once, but also individually, one at a time. So that when importing a new rule, the old ones are not deleted.

[Baton34]

This is a very necessary feature. Please add it.

[StVol33]

Yes! Please add it.

[didierfred]

thanks to @Baton34 the feature is merged in master branch and will be available in next release