DOC: Additions/updates documentation for df.interpolate() methods #60227
- [x] closes #60227 (Replace xxxx with the GitHub issue number)
- [ ] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.


### This PR improves the documentation for the `DataFrame.interpolate()` method and closes #60227

The focus is on providing more precise descriptions and examples for the following `method` options:

- **`method="index"`**: Emphasized that this method uses the actual numerical values of the index, which is particularly useful for non-sequential or time-based indices.
- **`method="time"`**: Expanded on the description to specify that this method interpolates based on the time intervals between observations, suitable for data with a time-based index.
- **`method="values"`**: Clarified that this method performs interpolation based on the actual numerical values within the DataFrame, treating them as equally spaced along the index.


### Changes Made

- Enhanced the docstring descriptions for `values`, `index`, and `time` methods in `DataFrame.interpolate()`.
- Added a practical example using a DataFrame with a non-sequential index to demonstrate the difference between `method="linear"` and `method="index"`.

@rhshadrach  Could you review this PR to improve documentation for df.interpolate() methods as part of issue #60227?” @rhshadrach  I've made the requested changes to the documentation. Could you please review it again? Thanks!
 Thanks @anishkarki 