Add Documentation on symbols and greek letters

[jellepoland]

Greek Letters

\alpha: angle of attack
\beta: side slip angle
\Gamma: Circulation

Symbol

[1-Bart-1]

\delta: angle of panel chordwise x-axis relative to body x-axis
\epsilon: trailing edge deformation angle relative to panel chordwise x-axis

[ufechner7]

The documentation exists: https://albatross-kite-transport.github.io/VortexStepMethod.jl/stable/glossary/

We only need to agree on the meaning of beta for example. And I am not sure if I like the suggested meaning of \epsilon. I would understand - if I see \epsilon - that this is the floating point machine error.

[ufechner7]

From my PhD thesis:

[ufechner7]

For me, beta is the elevation angle of the kite.

[ufechner7]

My suggestion:

1. $\delta$ (delta): angle of panel chordwise x-axis relative to body x-axis [rad]
2. $\lambda$ (lambda): trailing edge deformation angle relative to panel chordwise x-axis [rad]
3. $\alpha$ (alpha): angle of attack [rad]
4. $\beta$ (beta): elevation angle [rad)
5. $\beta_s$ (beta_s): side slip angle [rad]

[ufechner7]

Done: https://albatross-kite-transport.github.io/VortexStepMethod.jl/dev/glossary/