Added scripts to clear parsers/in and parsers/out after build:reference

[webermayank]

Fixes the issue #722

The following changes had been done in this PR

1. Added a function cleanUpDirectory in scripts/utils.ts
2. Call that function in reference.ts which will be executed at the end of all the processes to clean the cloned p5.js and p5.sound.js repo in scripts/parsers/in and out too

after that dev server is starting faster without any errors

@davepagurek tell me if anything need changes, i would love to do so

[davepagurek]

Nice, this looks good! Have you tried running npm run build:reference and then npm run dev? (Doing so will change a bunch of files in the reference folder that we don't want to commit just yet, so after testing you can run npm run custom:cleanup to clean those changes out.)

[webermayank]

Yes @davepagurek i tried npm run build:reference this has build the cloned repo along with some modifications in lots of files in reference/en directory files, and then npm run dev , the server started, and after that i did npm run custom:cleanup, the files that changes in reference/en reverted back hence everything worked perfectly without any errors

[davepagurek]

ok perfect, thanks for checking! This looks good to go then!