DOC: Rewriting of ParserError doc + minor spacing (pandas-dev#25421)

Follow-up to pandas-devgh-25414.

pandas/errors/__init__.py

@@ -9,17 +9,18 @@
 
 class PerformanceWarning(Warning):
     """
-    Warning raised when there is a possible
-    performance impact.
+    Warning raised when there is a possible performance impact.
     """
 
+
 class UnsupportedFunctionCall(ValueError):
     """
     Exception raised when attempting to call a numpy function
     on a pandas object, but that function is not supported by
     the object e.g. ``np.cumsum(groupby_object)``.
     """
 
+
 class UnsortedIndexError(KeyError):
     """
     Error raised when attempting to get a slice of a MultiIndex,
@@ -31,9 +32,15 @@ class UnsortedIndexError(KeyError):
 
 class ParserError(ValueError):
     """
-    Exception that is raised by an error encountered in `pd.read_csv`.
+    Exception that is raised by an error encountered in parsing file contents.
+
+    This is a generic error raised for errors encountered when functions like
+    `read_csv` or `read_html` are parsing contents of a file.
 
-    e.g. HTML Parsing will raise this error.
+    See Also
+    --------
+    read_csv : Read CSV (comma-separated) file into a DataFrame.
+    read_html : Read HTML table into a DataFrame.
     """
 
 
@@ -182,4 +189,4 @@ def __str__(self):
         else:
             name = self.class_instance.__class__.__name__
         msg = "This {methodtype} must be defined in the concrete class {name}"
-        return (msg.format(methodtype=self.methodtype, name=name))
+        return msg.format(methodtype=self.methodtype, name=name)