Paving the way to 0.5.0

[fjebaker]

It's been a few weeks since the last release, and much has changed in the main branch. This issue is to track what still needs to be done before 0.4.17 0.5.0 release:

• Documentation examples need to be updated and recomputed (Docs: update examples #168 )
• Rework radial disc profile #154 needs to be documented
• BeamedPointSource model added #150 needs to be documented
• Debugging coronal beaming emissivities #148 needs to be documented (debug toolkit)
• Feat: lag-frequency reverberation calculations #157 needs to be documented
• Feat: transfer functions for thick discs #141 needs to be documented
• Feat!: methods api #158 needs to be documented (breaking change)
• Consistent nomenclature and conventions #109
• Image planes can mismatch the desired sampled region #156
• Feat!: disc refactoring #161 needs to be documented
• Problems with the thick disc transfer functions #160
• Document impact parameter mapping #110
• Rename all equitorial projections and emission radii rho #166

[fjebaker]

Considering we are including breaking changes, we should release this as 0.5.0.