Awesome guide! That definitely deserves a couple of merit! 
I just have one minor correction:
What you do is use a BIP39 compatible seed (generated from https://iancoleman.io/bip39/ or a BIP39 wallet etc)... then when setting up the wallet, use "Standard wallet -> I already have a seed -> click "Options", select "BIP39 Seed" -> Enter your BIP39 seed, click Next -> You'll be prompted for derivation path, select "p2sh-segwit BIP49":
The derivation path will change to m/49'/0'/0' and the addresses generated with be the backwards compatible nested SegWit Addresses
I just have one minor correction:
Unfortunately, Electrum does not allow you to generate nested SegWit addresses which are backwards compatible.
That isn't entirely accurate. Electrum DOES allow you to create the "3"-type P2SH "nested" SegWit wallets... it just doesn't do it with "Electrum" seeds... only with BIP39 seeds and is probably not really a "beginner level" exercise. What you do is use a BIP39 compatible seed (generated from https://iancoleman.io/bip39/ or a BIP39 wallet etc)... then when setting up the wallet, use "Standard wallet -> I already have a seed -> click "Options", select "BIP39 Seed" -> Enter your BIP39 seed, click Next -> You'll be prompted for derivation path, select "p2sh-segwit BIP49":
The derivation path will change to m/49'/0'/0' and the addresses generated with be the backwards compatible nested SegWit Addresses