readme: add more instructions

README.md

@@ -5,4 +5,26 @@ Lite XL includes a shell file that does the job pretty well,
 but the aim here is to improve the experience more by making it actually
 useful.
 
-You will need to use Emscripten 3.1.57. Older versions may not work.
+## Instructions
+
+This repository is still a work-in-progress, so detailed instructions on how
+to set up everything is not available.
+
+In general, you will need the following tools:
+
+- Emscripten (optionally emsdk) 3.1.57 and newer. Older versions will not work.
+- wasm-dis (Installed with Emscripten if emsdk is used)
+- file_packager (Installed with Emscripten if emsdk is used)
+- watchexec (Optional)
+- A HTTP Server (I use `http-server`, but Python's `http.server` will work with caveats.)
+- Git
+- Bash (MSYS2 might work but not tested)
+- npm (Optional, for prettifying source code)
+
+Your entry point will be `build.sh`, which can be used to build and deploy the application.
+For most people, running `./build.sh` will be sufficient,
+or you could run `./build.sh -w` to automatically build the project when a file is changed.
+
+The generated file are available in `dist`.
+
+You can find specific documentation in each subfolder.