Add sample code for Nuitka standalone executable tutorial

[shabnomm]

Sample code for the "Nuitka: Compile Your Python Code Into a Standalone Executable" tutorial.

• wordcount.py: command-line word-count tool used throughout the tutorial
• cpu_benchmark.py: CPU-bound benchmark script used in the performance section
• sample.txt: sample input file for wordcount.py

[realpython-bot]

@shabnomm Relaying from @bzaczynski: two fixes are needed before this can merge, both found while checking the sample code against the tutorial.

1. sample.txt starts with a UTF-8 byte-order mark (bytes EF BB BF). Because wordcount.py reads the file with encoding="utf-8" rather than utf-8-sig, the first token becomes python, and the output is is: 3, popular: 2, python: 2, … instead of the python: 3, is: 3, … shown in the article. Please re-save the file without the BOM (in VS Code, click the encoding in the status bar, choose "Save with Encoding", then "UTF-8" rather than "UTF-8 with BOM").
2. README run command: ./wordcount.dist/wordcount should be ./wordcount.dist/wordcount.bin, matching the tutorial. While you're there, consider pinning python -m pip install nuitka==4.2.1 to match the article.

Nothing else needed. wordcount.py and cpu_benchmark.py match the tutorial exactly.

[shabnomm]

@bzaczynski Hi, I’ve fixed the sample.txt encoding and updated the README commands accordingly. Thank you.