Fix Sphinx homepage toctree rendering in index.md

[Copilot]

Describe your change

Sphinx docs were building, but the homepage content was effectively unusable because the root toctree in index.md was parsed as a code block instead of a directive. This PR corrects the MyST directive syntax so the homepage renders navigable docs content.

• Root cause
  • index.md used an invalid fenced directive form: ```text {toctree}
• Change made
  • Replaced it with valid MyST directive syntax: ```{toctree}
  • No workflow logic changes were needed in .github/workflows/sphinx.yml
• Snippet

  -```text {toctree}
  +```{toctree}
  :maxdepth: 2
  :caption: index.md

• Add an algorithm?
• Fix a bug or typo in an existing algorithm?
• Add or change doctests? -- Note: Please avoid changing both code and tests in a single pull request.
• Documentation change?

Checklist

• I have read CONTRIBUTING.md.
• This pull request is all my own work -- I have not plagiarized.
• I know that pull requests will not be merged if they fail the automated tests.
• This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
• All new Python files are placed inside an existing directory.
• All filenames are in all lowercase characters with no spaces or dashes.
• All functions and variable names follow Python naming conventions.
• All function parameters and return values are annotated with Python type hints.
• All functions have doctests that pass the automated testing.
• All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
• If this pull request resolves one or more open issues, then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

• Fixes Sphinx docs are not working #15314

[priya-sundaram-dev]

Nice catch on the root cause 👍 I reproduced this locally to confirm, and the diagnosis is exactly right:

• Before (```text {toctree}): MyST parses it as a plain text code block, so the directive never runs. The build emits document isn't included in any toctree for CONTRIBUTING.md, README.md, and LICENSE.md, and the homepage renders zero navigation entries.
• After (```{toctree}): the directive fires and the homepage gets a working table of contents (14 toctree-l1 links in my minimal repro).

One small follow-up while you're in here: with the directive now active, the HTML comment line inside the toctree body is treated as a doc reference and produces a warning:

index.md:3: WARNING: toctree contains reference to nonexisting document
'<!-- CONTRIBUTING.md must be the FIRST doc and README.md can come after. -->'

Directive bodies aren't Markdown, so the <!-- ... --> isn't stripped. Moving that note above the fence (or into :caption:) clears the warning and keeps the intent:

<!-- CONTRIBUTING.md must be the FIRST doc; README.md can come after. -->
```{toctree}
:maxdepth: 2
:caption: index.md

CONTRIBUTING.md
README.md
LICENSE.md

Verified locally that removing the comment line leaves a clean build with the full ToC. The `DIRECTORY.md` line in this PR looks like an unrelated auto-generated add. Core fix LGTM.

[cclauss]

In pre-commit:

rumdl fmt................................................................Failed
- hook id: rumdl-fmt
- files were modified by this hook

index.md:3:1: [MD040] Code block (```) missing language [fixed]

Fixed: Fixed 1/1 issues in 1 file (31ms)

https://rumdl.dev/md040 and https://rumdl.dev/md073

So we have to modify:

Python/pyproject.toml

Lines 235 to 244 in be65e47

	[tool.rumdl]
	disable = [
	# "MD013",
	"MD033",
	"MD036",
	"MD041",
	]
	exclude = [ "DIRECTORY.md", "docs/hacktober_2026_prep.md" ]
	flavor = "gfm"
	line-length = 350

to add...

per-file-ignores."index.md" = [ "MD040" ]

[cclauss]

Nice teamwork! Given enough eyeballs, all bugs are shallow.

[cclauss]

Zero files changed.