cosmetic changes in RST files (#341)

• Add ScrFile plot_freqs_at_ggp method

• Fix AttributeError: ‘Arrow3D’ object has no attribute ‘do_3d_projection’ raised by structure.plot()

• scr.reader –> scr.r, minor improvements in docs

• Don’t deploy website on pull requests

• Cosmetic changes

• More Type hints, fix a couple of sphinx warnings

• update vars database

• Fix a couple of RST warnings

• app post-processing tools for QHA