If I think it's interesting enough, I might implement separate interactive web pages to explain both the finite field arithmetic and the Reed-Solomon encoder LFSR. But if you look at these existing materials, I hope you agree with me that RS ECC encoding is long and tedious:

* https://www.embeddedrelated.com/showarticle/1182.php#c-imple...

* https://www.reddit.com/r/programming/comments/9th8a7/creatin...

* https://www.backblaze.com/blog/reed-solomon/

* https://en.wikiversity.org/wiki/Reed%E2%80%93Solomon_codes_f...

The author has that in an other article: https://www.nayuki.io/page/reed-solomon-error-correcting-cod...

You might be interested in https://www.akalin.com/intro-erasure-codes

He who?