fix: use extension in docs link so it also works on GitHub

[asterite]

Description

Problem

Resolves #6779

Summary

Additional Context

Documentation

Check one:

• No documentation needed.
• Documentation included in this PR.
• [For Experimental Features] Documentation to be submitted in a separate PR.

PR Checklist

• I have tested the changes locally.
• I have formatted the changes with Prettier and/or cargo fmt on default settings.

[github-actions]

Peak Memory Sample

Program	Peak Memory
keccak256	78.17M
workspace	122.03M
regression_4709	294.72M
ram_blowup_regression	2.44G
private-kernel-tail	208.76M
private-kernel-reset	861.45M
private-kernel-inner	307.68M
parity-root	174.42M

[github-actions]

Compilation Sample

Program	Compilation Time	%
sha256_regression	0m1.601s	7%
regression_4709	0m1.589s	4%
ram_blowup_regression	0m17.998s	5%
private-kernel-tail	0m1.520s	19%
private-kernel-reset	0m8.694s	-3%
private-kernel-inner	0m2.744s	18%
parity-root	0m0.850s	-26%
noir-contracts	2m39.392s	0%

[github-actions]

🚀 Deployed on https://675ac100955faa3072003f37--noir-docs.netlify.app

[github-actions]

FYI @noir-lang/developerrelations on Noir doc changes.