Add nwm_client documentation and minor subpackage level import changes

[aaraney]

Update / add too / fix issues with nwm_client readme and docstrings. Adds usage example for gcp client to readme.

Additions

• nwm_client submodule members, gcp and http can now be accessed from the subpackage level.

Checklist

• PR has an informative and human-readable title
• PR is well outlined and documented. See #12 for an example
• Changes are limited to a single goal (no scope creep)
• Code can be automatically merged (no conflicts)
• Code follows project standards (see CONTRIBUTING.md)
• Passes all existing automated tests
• Any change in functionality is tested
• New functions are documented (with a description, list of inputs, and expected output) using numpy docstring formatting
• Placeholder code is flagged / future todos are captured in comments
• Reviewers requested with the Reviewers tool ➡️

[jarq6c]

Appreciate the updated docs! Seems non-controversial. Just need some clarification on __init__.py imports (in terms of best practices/guiding philosophy/Pythonic-ness).

[jarq6c]

Is this a good idea?

[jarq6c]

By which I mean, we're not "polluting the namespace", right?

[aaraney]

Right, it's a matter of opinion and style. Personally, given our audience, I would like to make the experience using hydrotools as intuitive as possible. Here, I am assuming it is more intuitive to a user to import nwm_client and then tab complete to see the available submodules. Ex:

from hydrotools import nwm_client

# tab to see exposed subpackage level entities 
nwm_client. # tab tab

nwm_client.html, nwm_client.gcp 

To be fair, I am making a fair number of assumptions about how someone might use hydrotools. What do you think about my assumptions? To your point regarding clouding the namespace, im not sure im ready to answer that. I need to think about it more and consider what implications my assumptions might have.

[jarq6c]

Assuming you've mulled over the implications, let's see how it works out. No need for the PR to go stale because of this minor concern.

[jarq6c]

Link to #178
Link to #170
?