Fix recording slicing docstrings and documentation typo (#3939)

* Fix typo in combine_recordings.rst

* Update recording slicing docstrings describing default behavior

Author: kushaangupta

doc/how_to/combine_recordings.rst

@@ -4,7 +4,7 @@ Combine recordings in SpikeInterface
 In this tutorial we will walk through combining multiple recording objects. Sometimes this occurs due to hardware
 settings (e.g. Intan software has a default setting of new files every 1 minute) or the experimenter decides to
 split their recording into multiple files for different experimental conditions. If the probe has not been moved,
-however, then during sorting it would likely make sense to combine these individual reocrding objects into one
+however, then during sorting it would likely make sense to combine these individual recording objects into one
 recording object.
 
 **Why Combine?**

src/spikeinterface/core/baserecording.py

@@ -749,9 +749,9 @@ def frame_slice(self, start_frame: int | None, end_frame: int | None) -> BaseRec
         Parameters
         ----------
         start_frame : int, optional
-            The start frame, if not provided it is set to 0
+            Start frame index. If None, defaults to the beginning of the recording (frame 0).
         end_frame : int, optional
-            The end frame, it not provided it is set to the total number of samples
+            End frame index. If None, defaults to the last frame of the recording.
 
         Returns
         -------
@@ -771,9 +771,9 @@ def time_slice(self, start_time: float | None, end_time: float | None) -> BaseRe
         Parameters
         ----------
         start_time : float, optional
-            The start time in seconds. If not provided it is set to 0.
+            Start time in seconds. If None, defaults to the beginning of the recording.
         end_time : float, optional
-            The end time in seconds. If not provided it is set to the total duration.
+            End time in seconds. If None, defaults to the end of the recording.
 
         Returns
         -------