In short: You need text + diagramming tools. Go as light as possible, start small (draw.io and Markdown/AsciiDoc). Use high-end modeling tools (like Enterprise Architect or ArchiMate only in larger teams and/or with formal documentation requirements (20+ devs). Have a look at docToolchain.
I've written about requirements for docu-tools https://www.innoq.com/en/articles/2022/01/principles-of-tech...
In short: You need text + diagramming tools. Go as light as possible, start small (draw.io and Markdown/AsciiDoc). Use high-end modeling tools (like Enterprise Architect or ArchiMate only in larger teams and/or with formal documentation requirements (20+ devs). Have a look at docToolchain.