metasploit: explanation of the ASM source code of a general load, such as shell_reverse_tcp.asm

These days I am interested in knowing how useful metasplotables payloads work in the background.

I am not new to programming and, fortunately, the manageable goals comprise many interesting payloads with all the relevant source code.

However, I have run into the asm program (for example, this one that I would like to understand and study) and I have had very little experience with editing.

I was wondering if any of you could suggest a lesson / tutorial that explains this and / or other programs.

I searched the Internet and did not find any good resource and I really wanted to avoid trying to understand it with an ASM book alone. Thank you.