Implementations of the *traits* of the engines.
Engine's traits are fetched from the origin engine and stored in a JSON file in
the *data folder*. Most often traits are languages and region codes and their
mapping from SearXNG's representation to the representation in the origin search
engine.
To load traits from the persistence::
searx.enginelib.traits.EngineTraitsMap.from_data()
For new traits new properties can be added to the class::
searx.enginelib.traits.EngineTraits
.. hint::
Implementation is downward compatible to the deprecated *supported_languages
method* from the vintage implementation.
The vintage code is tagged as *deprecated* an can be removed when all engines
has been ported to the *traits method*.
Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
