Add var* versions of Greek letters

[Ricyteach]

Hi, I wanted to be able to use of the "alt" versions of lowercase Greek letters available in Latex, so I went ahead and added them (and to the readme as well):

• \varepsilon for ε and \epsilon for ϵ
• \theta for θ and \vartheta for ϑ
• \pi for π and \varpi for or ϖ
• \rho for ρ and \varrho for ϱ
• \sigma for σ and \varsigma for ς
• \varphi for φ and \phi for ϕ

Actually I was mostly just interested in \varphi and \varepsilon, but might as well include the others.

Anyway: please let me know if a PR like this is not welcome! Won't hurt my feelings. - Rick.

[connorferster]

@Ricyteach Thank you for the PR (and apologies on taking so long to review and merge). I appreciate the contribution!

The only changes I made were to add the "var greeks" to one of the test cases to make sure they get swapped out correctly.

[Ricyteach]

@Ricyteach Thank you for the PR (and apologies on taking so long to review and merge). I appreciate the contribution!

The only changes I made were to add the "var greeks" to one of the test cases to make sure they get swapped out correctly.

Perfect, great! Happy to helpl

I thought about trying to add a test but wasn't sure where to put it, thanks for the extra work.