add a tip to compile in watch mode

[xhliu]

at https://docs.scrypt.io/tutorials/hello-world#compile-contract and https://docs.scrypt.io/tokens/tutorials/ordinal-lock/#compile-contract, saying it will allow displaying sCrypt errors in real time in VSCode editor, as in https://docs.scrypt.io/installation#the-scrypt-cli-tool

Related https://github.com/sCrypt-Inc/scrypt-cli/issues/107 & https://github.com/sCrypt-Inc/scrypt-cli/issues/106

[yusufidimaina9989]

Done. https://github.com/sCrypt-Inc/scryptTS-docs/pull/242