[Sane-analysis] Update to inclusive pions wiki section

[O. A. Rondon]

I have updated my wiki section on Inclusive pion and nucleon
electroproduction adding an empirical correction to the epc code output
for high momentum inclusive pion electro- and photo-production on C nuclei.

I added a pion angle dependent normalization to minimize the chi squared
between the epc code output and the Yerevan 4.5 GeV pion photoproduction
 on C data, see item *Empirical modification of epc output* at

https://hallcweb.jlab.org/experiments/sane/wiki/index.php/Inclusive_pion_and_nucleon_electroproduction

The fit is
epc_corrected = epc_output*(a + b*angle^2), a=.171, b=.53, angle in
radians.

The data vs epc_corrected agreement is better than 20% for 40
deg., and smaller than a factor of 1.5 for most other points. The two
high p points for 60 deg. didn't improve

Since the data values come from digitized points from the published
plots they don't include errors, so the chi squared is a pseudo-chi
squared calculated as the squared ratio of the difference over the sum
of the data minus the epc output.

Given the strong angle dependence of the normalization I would not
recommend using other overall angle-independent normalizations, such as
the form A^.8, which is of unknown origin and ambiguous on how to use
(normalize pion production on H by A^.8? how about production on
neutrons? normalize to 2H?) Keep in mind that epc does calculate nuclear
cross sections already.

Cheers,

Oscar