OBIS API v3 docs suggestions

[7yl4r]

I am continuing an ongoing conversation with @pieterprovoost and @ayushanand18 here. To summarize discussion so far:

• The OBIS API documentation is comprised of:
  • the swagger endpoint api.obis.org
  • robis & pybobis docs
  • this manual

I have the following suggestions:

1. pagination of results from the API should probably be explained a bit.
2. a short note on how the usage of hasextensions might exclude a lot of results might be helpful.

I will suggest changes to address these once I have the extant swagger file(s).