more info about ipdb configuration (#14509)

IPython/core/debugger.py

@@ -14,14 +14,35 b' Among other things, this subclass of PDB:'
  - hide frames in tracebacks based on `__tracebackhide__`
  - allows to skip frames based on `__debuggerskip__`
 
+
+Global Configuration
+--------------------
+
+The IPython debugger will by read the global ``~/.pdbrc`` file.
+That is to say you can list all comands supported by ipdb in your `~/.pdbrc`
+configuration file, to globally configure pdb.
+
+Example::
+
+   # ~/.pdbrc
+   skip_predicates debuggerskip false
+   skip_hidden false
+   context 25
+
+Features
+--------
+
+The IPython debugger can hide and skip frames when printing or moving through
+the stack. This can have a performance impact, so can be configures.
+
 The skipping and hiding frames are configurable via the `skip_predicates`
 command.
 
 By default, frames from readonly files will be hidden, frames containing
-``__tracebackhide__=True`` will be hidden.
+``__tracebackhide__ = True`` will be hidden.
 
-Frames containing ``__debuggerskip__`` will be stepped over, frames who's parent
-frames value of ``__debuggerskip__`` is ``True`` will be skipped.
+Frames containing ``__debuggerskip__`` will be stepped over, frames whose parent
+frames value of ``__debuggerskip__`` is ``True`` will also be skipped.
 
     >>> def helpers_helper():
     ...     pass
@@ -1070,7 +1091,9 b' class Pdb(OldPdb):'
                 raise ValueError()
             self.context = new_context
         except ValueError:
-            self.error("The 'context' command requires a positive integer argument.")
+            self.error(
+                f"The 'context' command requires a positive integer argument (current value {self.context})."
+            )
 
 
 class InterruptiblePdb(Pdb):