JLBLine/WODEN: Frequency-smooth MWA primary beams

This release adds two new primary beam models:

• --MWA_FEE_interp - adds the ability to use the new hdf5 MWA Fully Embedded Element (FEE) file MWA_embedded_element_pattern_rev2_interp_167_197MHz.h5, which contains frequency interpolated coefficients. At the time of this release, this file was unpublished. If the documentation doesn't specify how to obtain the file yet, please contact jack.line@curtin.edu.au to obtain/discuss. This file only spans the frequencies between 167 and 197 MHz
• --MWA_analy - An analytic version of the MWA primary beam. Not as accurate as the MWA FEE beam, but covers all frequencies, allowing smooth spectral behaviours at all frequencies.

Both new modes have had tests written for them, and updated documentation.

Full Changelog: https://github.com/JLBLine/WODEN/compare/v1.1.0...v1.2.0