Build documentation could use more specifics

[FerrazArthur]

After building the whole project, as in the README, i'm left with a bunch of compacted files of with i have no clue what to do next. i just wish to install the whole package and use it to turn my c++ code into wasi compatible. I feel like i wasted time building the whole thing, just to afterwards follow the "install" instructions, that doesnt need the "build" process.

[frawamudi]

Current facing same issues. please more details would be nice to have especially when it come to using the wasi tool chain file.