New module for NMO correction

[leouieda]

Based on the code for the NMO The Leading Edge tutorial:
https://github.com/pinga-lab/nmo-tutorial

Adds a nmo_correction function to seismic that applies the
correction to a given CMP using an NMO velocity profile.

Checklist:

• Make tests for new code (at least 80% coverage)
• Create/update docstrings
• Include relevant equations and citations in docstrings
• Docstrings follow the style conventions
• Code follows PEP8 style conventions
• Code and docs have been spellchecked
• Include new dependencies in doc/install.rst, environment.yml, ci/requirements-conda.txt and ci/requirements-pip.txt.
• Documentation builds properly (run cd doc; make locally)
• Changelog entry (leave for last to avoid conflicts)

[eusoubrasileiro]

@leouieda is this tutorial already published? Really nice job! You are getting new cool partner's, pro working with pros. Amazing that you are moving to the dark side haha haha

[leouieda]

@eusoubrasileiro the tutorial will be out in February but the text and notebook are done and available in the repository. I couldn't get binder link to work so I'll probably delete that part. But you should be able to run it offline.