docs: improve docs for the random walk operator

[danielelotito]

Small fixes to the docs.
Notably the rendering of nested lists is not correct on the website, see e.g. https://ibm.github.io/ado/operators/random-walk/#batch-size-and-concurrent-experiments

While, mkdocs serve correctly displays nested lists.
Note that with ec27daf I committed a double indentation on a nested list.

Please do whatever appropriate to inspect and fix this.

[AlessandroPomponio]

Please make sure the style matches the one defined in https://github.com/IBM/ado/blob/main/CONTRIBUTING.md#coding-style-guidelines

Currently, the following errors are reported by markdownlint-cli2:

The following files are missing headers:
markdownlint-cli2 v0.18.1 (markdownlint v0.38.0)
Finding: **/*.md !.venv
Linting: 72 file(s)
Summary: 6 error(s)
website/docs/operators/random-walk.md:39:81 MD013/line-length Line length [Expected: 80; Actual: 116]
website/docs/operators/random-walk.md:123:81 MD013/line-length Line length [Expected: 80; Actual: 135]
website/docs/operators/random-walk.md:175:1 MD007/ul-indent Unordered list indentation [Expected: 2; Actual: 4]
website/docs/operators/random-walk.md:176:1 MD007/ul-indent Unordered list indentation [Expected: 2; Actual: 4]
website/docs/operators/random-walk.md:178:1 MD007/ul-indent Unordered list indentation [Expected: 2; Actual: 4]
website/docs/operators/random-walk.md:179:1 MD007/ul-indent Unordered list indentation [Expected: 2; Actual: 4]

The first two can be fixed, while I think the CLI does not understand that the indentation of the list is intended. For that, you can add a comment like

<!-- markdownlint-disable ul-indent -->
(the list)
<!-- markdownlint-enable ul-indent -->

But it's also worth trying to see if changing the indentation level works

[AlessandroPomponio]

LGTM thanks!

[DRL-NextGen]

Checks Summary

Last run: 2025-09-17T08:15:24.154Z

Code Risk Analyzer vulnerability scan found 1 vulnerabilities:

Severity	Identifier	Package	Details	Fix
◻Unknown	CVE-2025-58446	xgrammar	xgrammar vulnerable to denial of service by huge enum grammar GHSA-9q5r-wfvf-rr7f xgrammar:0.1.23->vllm:0.10.2	0.1.24