check that description of cdf format is consistent with other formats

[nickreich]

https://hubdocs.readthedocs.io/en/latest/user-guide/model-output.html#formats-of-model-output

Noting a small point of confusion. I was surprised to see that

• the quantile-level was in output_type_id and the quantile forecast in value
• the x-value for the cdf was in output_type_id and the cdf in value. To me it felt a bit inconsistent that the "real world value" was once in value and once in output_type_id. I'm sure there are good reasons for this, just noting it in case it is useful as feedback.

Originally posted by @nikosbosse in https://github.com/Infectious-Disease-Modeling-Hubs/hubUtils/discussions/125#discussioncomment-7575266

[aaronger]

https://github.com/Infectious-Disease-Modeling-Hubs/hubUtils/discussions/125#discussioncomment-7622142

[nickreich]

NVM - this is a non-issue afterall. See https://github.com/Infectious-Disease-Modeling-Hubs/hubUtils/discussions/125#discussioncomment-7626164