Update README.md

[ghostant-1017]

sudo is needed because it will try to install solc if solc is not installed, and it will failed if not sudo.

Downloading solc 0.7.6
Error HH501: Couldn't download compiler version 0.7.6+commit.7338295f. Please check your internet connection and try again. 

[github-actions]

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[ghostant-1017]

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[mmv08]

sudo is not required to install a compiler and npm dependencies