docs: pass project manifest to miden build

[huklaa]

Fixes #210.

Updates the Miden Bank quick-start README and Part 0 setup guide to pass miden-project.toml explicitly to miden build, matching the maintainer guidance in #210 for toolchains where miden build invokes midenc directly.

This keeps the existing miden workflow while avoiding the expected input file failure.

[TomasArrachea]

Once 0xMiden/midenup#234 lands on midenup, this will no longer be necessary. Users should use miden build directly instead of having to specify the input file.

[huklaa]

Thanks, that makes sense. I’ll leave #223 open while 0xMiden/midenup#234 is still pending, and close this PR once that lands if the docs change is fully redundant.