[llvm] [Docs] Add CIBestPractices docs link to Reference.rst (PR #165108)

[Baranov Victor via llvm-commits]

https://github.com/vbvictor created https://github.com/llvm/llvm-project/pull/165108

Based on https://github.com/llvm/llvm-project/pull/165067#issuecomment-3446142541.

>From 377bff4d46f7d48ce3ce85a221e336a8cf790730 Mon Sep 17 00:00:00 2001
From: Victor Baranov <bar.victor.2002 at gmail.com>
Date: Sat, 25 Oct 2025 19:34:46 +0300
Subject: [PATCH] [Docs] Add CIBestPractices docs link to Reference.rst

---
 llvm/docs/Reference.rst | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/llvm/docs/Reference.rst b/llvm/docs/Reference.rst
index 9b1bf1be9c8bf..212aefa0e73fb 100644
--- a/llvm/docs/Reference.rst
+++ b/llvm/docs/Reference.rst
@@ -250,3 +250,7 @@ Additional Topics
 
 :doc:`ContentAddressableStorage`
    A reference guide for using LLVM's CAS library.
+
+:doc:`CIBestPractices`
+   A list of guidelines and best practices to use when working on LLVM's
+   CI systems.