Add C++ implementation; update Python version (#756)

Author: rayokota

docs/overview.md

@@ -23,13 +23,14 @@ The following are known implementations of JSONata in addition to the primary im
 |Language|Link|Notes|JSONata version|
 |---|---|---|---|
 |C|https://github.com/qlyoung/jsonata-c|Runs JSONata in embedded JS engine|1.8.3|
+|C++|https://github.com/rayokota/jsonata-cpp|Native port of reference|2.1.0|
 |Go|https://github.com/blues/jsonata-go|Native implementation|1.5.4|
 |Go|https://github.com/yxuco/gojsonata|Native implementation| |
 |Java|https://github.com/IBM/JSONata4Java|Native implementation| |
 |Java|https://github.com/dashjoin/jsonata-java|Native port of reference|2.0.5|
 |.NET|https://github.com/mikhail-barg/jsonata.net.native|Native implementation|1.8.5|
 |Python|https://github.com/qlyoung/pyjsonata|API bindings based on C bindings|1.8.3|
-|Python|https://github.com/rayokota/jsonata-python|Native port of reference|2.0.5|
+|Python|https://github.com/rayokota/jsonata-python|Native port of reference|2.1.0|
 |Rust|https://github.com/johanventer/jsonata-rust|Implementation work in progress| |
 |Rust|https://github.com/Stedi/jsonata-rs|Actively-developed fork of jsonata-rust| |