DOC: slim parameter description not documented in OLS.summary()

[TremaMiguel]

Describe the bug

Checking the source code for OLS.summary() function there's an slim which does not appears in the documentation.

When you set slim=True one expects not to get the following information in the model summary.

diagn_left = [('Omnibus:', ["%#6.3f" % omni]),
                          ('Prob(Omnibus):', ["%#6.3f" % omnipv]),
                          ('Skew:', ["%#6.3f" % skew]),
                          ('Kurtosis:', ["%#6.3f" % kurtosis])
                          ]

diagn_right = [('Durbin-Watson:',
                ["%#8.3f" % durbin_watson(self.wresid)]
                ),
               ('Jarque-Bera (JB):', ["%#8.3f" % jb]),
               ('Prob(JB):', ["%#8.3g" % jbpv]),
               ('Cond. No.', ["%#8.3g" % condno])
               ]