Docs: Update ID language for RawIO

[zm711]

@h-mayorquin how does this look for tweaking the docs?

[h-mayorquin]

I think this is an improvement but maybe we should note that index are ambiguos in the sense that we might change what they address. That is, they are unstable.

[zm711]

It's a bit hard for me to figure out the best way to word that. In an individual version of Neo they are stable right? It is just between files/versions that we are drifting a bit? Do you have any ideas for how you want to say it and I can clean up the final language?

[h-mayorquin]

If it were up for me I would not mention indices at all. They should be an internal detail of the implementation.

[zm711]

Unfortunately they are not currently an internal detail so we have to let users know they exist and are usable.

[h-mayorquin]

Looks good to me. Small things: "capabilitiies" typo, and the paragraph mixes "ID", "ids" and "IDs". If you want to capture the stability point, maybe something like: "Indices are positional and only stable within a given version of Neo; a reader update (for example adding digital channels) can change which channel an index points to. If your code needs to work across Neo versions, select by ID." Fine either way.

[zm711]

I will add your fixes then merge! Indices is better in my opinion but the argument name is indexes so I'll take that to keep it consistent. Thanks!