Add Logs Ingestion API scenario with synthetic sample data

[austinmccollum]

Summary

Adds a new scenario under Scenarios/How to collect data with the Logs Ingestion API/ to support the Logs Ingestion API portal tutorial.

Problem

The tutorial's inline sample data (~200 lines of Apache access logs) contained references to a real website (almhuette-raith.at), real page paths, and real user-agent strings — a privacy concern for published documentation.

Changes

File	Description
README.md	Describes the scenario, links to the tutorial, explains the sample data and generator script
Generate-SampleAccessLog.ps1	PowerShell script that generates synthetic Apache Combined Log Format entries with configurable count. Uses RFC 5737 documentation IPs (198.51.100.x, 203.0.113.x), contoso.example.com domains, and weighted response codes
sample_access.log	Pre-generated 200-entry synthetic log file, ready to use with the tutorial

Design decisions

• RFC 5737 IPs (198.51.100.x, 203.0.113.x) and RFC 2606 domains (example.com) — reserved for documentation, guaranteed non-routable
• Weighted response codes — 65% 200, 8% 404, 8% 304, plus 301/400/401/403/500/502/503 — ensures the tutorial's where ResponseCode != 200 KQL filter produces meaningful output
• Fixed random seed (42) in the generator for reproducibility
• Varied user agents — desktop, mobile, bot, CLI — realistic mix without real device fingerprints