DOC: Additions/updates documentation for df.interpolate() methods pan…

…das-dev#60227 (pandas-dev#60247)

* DOC: Improve documentation for df.interpolate() methods pandas-dev#60227

* DOC: Fix rounding in DataFrame.interpolate index method example

* Fix: Use index method for linear interpolation with non-sequential index

* Refactor: Rename DataFrame variable for non-sequential index

* Refactor: Added Example for non-sequential dataframe at the end of docstring

* CLN: Remove trailing whitespace in docstring and adding comment

* DOC: Revert added non-sequential index example in interpolate() docstring

* Update pandas/core/generic.py

Co-authored-by: Richard Shadrach <[email protected]>

* Update pandas/core/generic.py

Co-authored-by: Richard Shadrach <[email protected]>

* Trigger CI

* Trigger CI

---------

Co-authored-by: anishkarki <swordfish@DESKTOP-F6H5D41>
Co-authored-by: Richard Shadrach <[email protected]>

pandas/core/generic.py

@@ -7668,8 +7668,12 @@ def interpolate(
             * 'linear': Ignore the index and treat the values as equally
               spaced. This is the only method supported on MultiIndexes.
             * 'time': Works on daily and higher resolution data to interpolate
-              given length of interval.
-            * 'index', 'values': use the actual numerical values of the index.
+              given length of interval. This interpolates values based on
+              time interval between observations.
+            * 'index': The interpolation uses the numerical values
+              of the DataFrame's index to linearly calculate missing values.
+            * 'values': Interpolation based on the numerical values
+              in the DataFrame, treating them as equally spaced along the index.
             * 'nearest', 'zero', 'slinear', 'quadratic', 'cubic',
               'barycentric', 'polynomial': Passed to
               `scipy.interpolate.interp1d`, whereas 'spline' is passed to