Just be aware of the risks involved with running your own CA.
You’re adding a root certificate to your systems that will effectively accept any certificate issued with your CA’s key. If your PK gets stolen somehow and you don’t notice it, someone might be issuing certificates that are valid for those machines. Also real CA’s also have ways to revoke certificates that are checked by browsers (OCSP and CRLs), they may employ other techniques such as cross signing and chains of trust. All those make it so a compromised certificate is revoked and not trusted by anyone after the fact.
For what’s worth, LetsEncrypt with DNS-01 challenge is way easier to deploy and maintain in your internal hosts than adding a CA and dealing with all the devices that might not like custom CAs. Also more secure.
Nobody does that. People simply store HTML, Markdown or BB code. Check out TinyMCE, Milkdown, tui-editor, stackedit… all of them have a “see source” button and you’ll see the text with the formatting code right there.