[YAML thing] Allow "configuration" in syntax as alternative to "config"

[lolodomo]

For thing and channel.

[holgerfriedrich]

Could you pls. give some context why you want to add this alias? Is this a planned transition or are there inconsistencies?

[lolodomo]

It is to keep a kind of consistency with what @Nadahar implemented in #4633 . I found his proposal reasonable, even if of course not strictly required.

[Nadahar]

My reason for wanting to support both is that "the new YAML format" has defined its own shorthand terms for various fields for convenience. But, for anyone working with the actual Java class structure as a guide, or using JSON DB serializations as inspiration, these shorthand terms will be unknown, and they would have to find the documentation where these are "translated" to make things work. It costs so little to support the "full name" in addition to the shorthand terms, which I believe may result in a smoother experience all in all.

[holgerfriedrich]

Thanks for the explanation.