Add Zambia Registrar of Societies zm-rs.json. Fixes #709

[mdpointer]

Not good lookup options for this list

[emmajclegg]

Thanks @mdpointer - just added the one comment above. Happy for this to go live once that edit's made.

[mdpointer]

Thanks @emmajclegg I can't seem to see a comment anywhere - am I going mad?

[emmajclegg]

@mdpointer - it should be visible on the conversation thread for the pull request: #726

Copied here (it relates to the list description field):

I suggest removing the last line of this description, as it's included in the using identifiers section below: "Registration numbers issued by this office follow the format ORS/[3-digits]/[2-digits]/[3-digits] (e.g. ORS/102/35/225). When used as an identifier, the ORS prefix and the hyphens should be removed (e.g. 10235225)."

Also, if registration is subject to annual renewal, we should confirm that registration numbers don't change (if we understand that to be the case). A quick online search suggests that they don't change once allocated.