Add module scoping to unexported functions in docs

[kimlaberinto]

I noticed that some code examples in the docs didn't have module scoping where it needed it.

Referencing the HISTORY.md and #699 , I looked for the un-exported functions in the docs (using the following command snippet).

cd docs/
grep -RIn -Ei "(file\(|filename\(|name\(|get_chunk\(|get_datasets\(|iscontiguous\(|ishdf5\(|ismmappable\(|root\(|readmmap\(|set_dims\!\(|get_access_properties\(|get_create_properties\(|create_external_dataset\()" . -C 3

(the grep line is to look for each function in the list with a parenthesis e.g ismmappable( in the docs folder and display them to console with 3 lines of context.)

I then manually added HDF5 scoping to them I thought appropriate.

I haven't checked if the code works for every single one but I checked a few simple ones like HDF5.immappable and it works. I wanted to touch base with you all (the maintainers) to see if I should double check all the code snippets, or if you think this should be good.

Let me know if there might be more unexported functions that I missed in the docs or if there's anything I should change. Otherwise I think it should be ready to merge/review.

[kimlaberinto]

Now I also checked the functions referenced in src/HDF5.jl but nothing came up. So those functions should also be good to go.

grep -RIn -EI "(iscompact\(|ischunked\(|refresh\(|start_swmr_write\(|create_external\()" docs/ -C 3 

So all of these functions listed in src/HDF5.jl I now checked in the docs and should be good. (copied from src/HDF5.jl)

### The following require module scoping ###

# file, filename, name,
# get_chunk, get_datasets,
# get_access_properties, get_create_properties,
# root, readmmap, set_dims!,
# iscontiguous, iscompact, ischunked,
# ishdf5, ismmappable,
# refresh
# start_swmr_write
# create_external, create_external_dataset

[jmert]

Thank you for the contribution! Docs are something I (we) haven't gotten around to improving as much as I'd hoped, so thank you.

Just a quick review looks good to me, and it's not an error to "unnecessarily" scope a call, so I think this is a safe change. (Not saying this is unnecessary, just that not having explicitly checked, it's OK to be wrong.)

[kimlaberinto]

Thank you! And you're very welcome! Thank you for the Julia package

Feel free to merge :)

[jmert]

@musm It appears the docs preview deploy is errorring but CI didn't fail. Not a barrier to merging this PR, but something we should probably look into.

[musm]

I don't think doc deploys work on forks

[musm]

Whops sorry @jmert that wasn't what you are refering to. Indeed, let me investigate..