example for ParameterScan from docs broken

[SchwarzMarek]

Hello,
I've encountered few issues when trying to use ParameterScan interface.

1. plotSurface example
   based on online docs (https://tellurium.readthedocs.io/en/latest/paramscan.html) the plotSurface() example fails with:

File ~/miniconda3/envs/tell/lib/python3.11/site-packages/tellurium/analysis/parameterscan.py:411, in ParameterScan.plotSurface(self)
    408 Z = result[2]
    410 fig = plt.figure()
--> 411 ax = fig.gca(projection='3d')
    412 if self.antialias is False:
    413     surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1, cmap=self.colormap,
    414                            antialiased=False, linewidth=0)

TypeError: FigureBase.gca() got an unexpected keyword argument 'projection'

te.__version__
'2.2.8'
matplotlib.__version__
'3.8.3'
sys.version
'3.11.7 | packaged by conda-forge | (main, Dec 15 2023, 08:38:37) [GCC 12.3.0]'

(I know, that my te version is behind, but the problematic line (https://github.com/sys-bio/tellurium/blob/8652c7f79505889f947d63d444967972f4e4dd38/tellurium/analysis/parameterscan.py#L273C22-L273C38) is still present in github code; this might have some related info: https://stackoverflow.com/questions/76047803/typeerror-figurebase-gca-got-an-unexpected-keyword-argument-projection)

2. plot2DParameterScan example
   This part of the docs is probably old and does not reflect current code in classes (not functions as in the docs).

I was able to obtain some results with following modification to docs code:

# model definitions
r = te.loada("""
model test
   J0: S1 -> S2; Vmax * (S1/(Km+S1))
    S1 = 10; S2 = 0;
    Vmax = 1; Km = 0.5;
end
""")
s = r.simulate(0, 20, 41)
r.plot(s)

a = te.analysis.parameterscan.ParameterScan2D(r,
                    p1='Vmax', p1Range=np.linspace(1, 10, num=5),
                    p2='Vmax', p2Range=np.linspace(0.1, 1.0, num=5),
                    start=0, end=50, points=101)
a.plotMultiArray()

Best
M.