Ready to run (#833)

* misc: exclude ready-to-run dir in gitignore

* misc: update ready-to-run flow

* misc: update nemu-so

* readme: use nemu-so in ready-to-run

README.md

@@ -77,7 +77,7 @@ Some of the key directories are shown below.
 Example:
 ```bash
 make emu CONFIG=MinimalConfig SIM_ARGS=--disable-log EMU_THREADS=2 -j10
-./build/emu -b 0 -e 0 -i ./ready-to-run/coremark-2-iteration.bin
+./build/emu -b 0 -e 0 -i ./ready-to-run/coremark-2-iteration.bin --diff ./ready-to-run/riscv64-nemu-interpreter-so
 ```