Barbanis2D a few fixes are needed

[broncio123]

• Hyperlinks referencing to equations, not rendering although equation labels are defined

This seems easy to fix but needs to clean equation syntax-lines from comments and maybe play around with LaTeX syntax (use Jupyter for testing)

• Fix inline references to (sub)sections

Section labels are missing and spurious references to Appendix sections appear throughout the text.

• Fix figure caption heading

Change fig:1 for Fig:1, for instance. Also, remove redundant Fig. fig:1 inline references (already raised in #62 ).