Rule of thumb for when JLSO is inefficient in terms of file size

[cossio]

Regarding this note from the Readme:

Note: If the amount of data you have to store is very small, relative to the metadata about your environment, then JLSO is a pretty suboptimal format.

I'd say it's not clear when JLSO is or is not efficient to store your data.
Perhaps this note can be extended, to clarify this explicitly:

Note: If the amount of data you have to store is very small, relative to the metadata about your environment, then JLSO is a pretty suboptimal format. As a rule of thumb, consider the size of your Project.toml and Manifest.toml files. If the data you are storing is large compared to the size (compressed) of these files, then it is fine to use JLSO.

If people agree I can do a PR.