Late to this! I am making a BG3 webcomic. I did a lot of research and have been working on it for about 2 years in my off time.
I actually did a ton of research and I have some books and tools I strongly recommend. However, my disclaimer is: the best tools/frameworks/methods are whatever get you to actually be consistent and just start. One of the best things that got me through the thumbnailing of my prologue (which ended up being about 55 pages) was just to dedicate to drawing 5 minutes a day and doing something small comic related a day.
Consistency is the biggest killer in webcomics. That being said, my recommendations:
Programs: clip studio for actual comic stuff. I did all of my finished comic stuff in clip studio and I strongly recommend it over other programs because it just has a lot of shit in it that would take several other programs to accomplish (some of my favorite features are the 3D models which include a hand scanner that can scan your hand with your camera in real time to a displayed 3D model), being able to switch around all the windows, and just the assets store in general.
However, a lot of the functions can be replicated with a ton of other programs, clip is just kind of a swiss army knife of art programs. The lettering and effects tools can be frustrating to learn at first but then it's very worth it.
Procreate is basically the opposite, it's like made to be as barebones as possible to just get a more naturalistic digital drawing experience. It's also ipad only but if you have an ipad I recommend it to just draw if you don't wanna just do paper. It's also 10 bucks solid purchase no subscription.
As for books: I read a few on comics and unfortunately most of the books aren't super applicable to webcomics as a medium bc they're oriented towards comics professionals in the Western big professional comics industry (so more superhero stuff, no diss to them, I'm a Batman Stan!)
My recommendations are the first two Scott McCloud understanding comics books, the third one is like... Not super relevant. You can skip the Will Eisner books tbh, Scott McCloud mostly reiterates the same information without drawing and reiterating some problematic caricatures lol. (it's like, BAD PEOPLE HAVE HOOK NOSES AND AFROS, it's alright, you're not missing much)
Lynda Barry's books are like... Not really about comics as a serious sequential art concept but more like art therapy if you feel like shit. Can't recommend them if you have a story you're trying to accomplish.
The best and most completed book i read is for sure How to Webcomic by that starfish uh... Like that's their username but it's a real book, they have a YouTube channel. It's incredibly comprehensive about the medium of webcomics specifically - it's super good.
As for website stuff, I don't use eleventy specifically but I had great luck with the rarebit layout, although I had NO javascript experience so I had to have a friend explain it to me bc it really didn't come with documentation.