Support Nodejs v20, drop support for v14

[wayneparrott]

Proposed workflow changes:

1. Nodejs v20 is the current version in development. I propose we modify the workflow to include testing on node v20.

2. Node v14 recently reached end-of-life status. Therefore I propose we drop it from the workflow.

[minggangw]

Agree, we can drop node 14 now, thanks!

[minggangw]

I have updated the documentation for the changes of supported nodejs versions, please check #17

[dineshHarikrishnan]

Proposed workflow changes:

1. Nodejs v20 is the current version in development. I propose we modify the workflow to include testing on node v20.
2. Node v14 recently reached end-of-life status. Therefore I propose we drop it from the workflow.

When can I expect the stable release for the nodeJs version 20?

[chfritz]

@dineshHarikrishnan we are using node 20 in Transitive (which is installed and running on a lot of robots) and rclnodejs is working fine with it, e.g., in ros-tool. Is it not working for you?