chore: Replace scikit-package-logo-text.png and example-table.rst with placeholder files, fix docformatter for arbitrary.py

Author: kwagoner94

doc/source/img/.placeholder

@@ -67,6 +67,9 @@ skip = "*.cif,*.dat"
 recursive = true
 wrap-summaries = 72
 wrap-descriptions = 72
+exclude = [
+  "src/diffpy/srmise/baselines/arbitrary.py"
+]
 
 [tool.black]
 line-length = 115

doc/source/img/scikit-package-logo-text.png

@@ -26,16 +26,17 @@
 class Arbitrary(BaselineFunction):
     """Methods for evaluating a baseline from an arbitrary function.
 
-    Supports baseline calculations with arbitrary functions.  These
-    functions, if implemented, must have the following signatures and
-    return values: valuef(pars, x) ==> numpy.array of length x if x is a
-    sequence               ==> number if x is a number jacobianf(pars,
-    x, free) ==> list, each element a numpy.array of length x if
-    x is a sequence or None if value of free for
-    that parameter is False.                         ==> list, each
-    element a number if x is a number                             or
-    None if value of free for that parameter is
-    False estimatef(x, y) ==> numpy.array of length npars
+    Supports baseline calculations with arbitrary functions.  These functions,
+    if implemented, must have the following signatures and return values:
+    valuef(pars, x)          ==> numpy.array of length x if x is a sequence
+                             ==> number if x is a number
+    jacobianf(pars, x, free) ==> list, each element a numpy.array of length x if
+                                x is a sequence or None if value of free for
+                                that parameter is False.
+                             ==> list, each element a number if x is a number
+                                or None if value of free for that parameter is
+                                False
+    estimatef(x, y)          ==> numpy.array of length npars
     """
 
     def __init__(self, npars, valuef, jacobianf=None, estimatef=None, Cache=None):