Update keywords.txt with freshly added types

[aentinger]

Both namespaces and classes.

[aentinger]

Hell, maybe someone could write a tool perusing all the wrappers and extracting all namespaces and classes.

[per1234]

I have collected a list of potential tools here: per1234/arduino-ci-script#17
Never got around to looking into it closely though.

[aentinger]

That would be terrific if one of those tools could be repurposed! 💯

[aentinger]

After mediating on it I believe this is no longer relevant. There are simply too much types and the benefit is rather minimal.