Refactor docs and make Input API more explicit (#235)

tests/openvm/basic/src/main.rs

@@ -1,10 +1,9 @@
 use ere_platform_openvm::OpenVMPlatform;
 use ere_test_utils::{
-    guest::Sha256,
     io::serde::bincode::BincodeLegacy,
     program::{basic::BasicProgram, Program},
 };
 
 fn main() {
-    BasicProgram::<BincodeLegacy>::run::<OpenVMPlatform<Sha256>>();
+    BasicProgram::<BincodeLegacy>::run_output_sha256::<OpenVMPlatform>();
 }

tests/openvm/stock_nightly_no_std/src/main.rs

@@ -1,10 +1,12 @@
 #![no_std]
 #![no_main]
+
 extern crate alloc;
 
 use alloc::vec::Vec;
-use core::sync::atomic::Ordering;
 use core::sync::atomic::AtomicU16;
+use core::sync::atomic::Ordering;
+
 mod openvm_rt;
 
 fn main() {