New context kb-macro.active

[tshino]

I'm going to introduce a new Boolean context kb-macro.active which indicates that wrapper keybindings are enabled.

Currently, the context used on wrapper keybindings is kb-macro.recording which indicates that the recording is ongoing.
It means that unless the user starts a recording macro the wrapper keybindings won't be activated.
Although that is true by the design of this extension, the two concepts could be separated.
And it turned out that the two concepts must be separated to realize a new feature.
The new feature which needs the new context to be introduced is #125.

The plan is as follows:

1. Introduce kb-macro.active as an alias of kb-macro.recording.
2. Publish a new version. This is to mitigate the dependency issue between the binary and the document.
3. Update the document to describe users should use kb-macro.active instead of kb-macro.recording on wrapper keybindings.
4. Update the scripts that generate wrapper keybindings to use kb-macro.active instead of kb-macro.recording.
5. Update the wrapper keybindings in package.json by running the updated script.
6. Update the keymap wrappers by running the updated script.
7. Update CHANGELOG
8. (optional) Publish a new version.

These changes are not meant to be a breaking change for existing users.
If an existing user doesn't notice this change and even updates this extension to the new version, no noticeable change should happen.

[tshino]

Finally, Done!