Lua is closed to Conky, you need to check your theme then try to modify it little by little inside to understand how it works… then use the Lua link I gave to add what you want…
From your link, I clicked on the readme.md file that suppose to give you informations !
You will find also info about More details about the start screen…
The Lockscreen and dotfiles you found are for AwesomeWM, a Window-Manager completely configured in LUA. For KDE/Plasma this won’t help you.
If you want to finetune your system in every little detail (with config files) you maybe want to try i3wm or bspwm (similar to AwesomeWM). Of course you should get some information about those before. Windowmanagers are very basic and you have to configure yourself everything you want but it’s fun when you get into it. Just a thought.
Ok so I am looking at this article (based on the links you have sent me through redit) and I quote from the website
Themes are stored in respective subfolders of share/plasma/desktoptheme. A theme is described by a metadata.desktop file in the top-level directory of such a subfolder.
I get that I can see some of the themes. But through global themes I installed chromeOS theme, but it doesn’t show the folder.
The DE we proposed on EndeavourOS are vanilla means it’s the original default Plasma that you have… then you are free to build or personnalize the theme you would like…
you could imagine that if we bring lot of themes predefined in each DE we are proposing, at the end in spite to have an ISO of 1.6Go it would be bigger.
then EndeavourOS will not choose for you what you like but will give you the possibility to choose what you want.
Read this could help you to understand how to setup your theme
From the WM-side I only used i3wm. I would suggest to look at some config-files and judge yourself if you could achieve what you want with them.
A quick Duckduckgo-search provide you some…
As for Plasma you are looking in the wrong place. The themes you downloaded are in your home-folder:
Tell Dolphin to show the hidden files. (CTRL+H is a standard shortcut for that)
Take a look in /usr/share/sddm/themes/ and duplicate anything you find there. Then work on changing bits of code / artwork following the resource at https://github.com/sddm/sddm/wiki/Theming