allow json module imports

[technophile-04]

Description

This allows importing json in .ts files for example in scripts.

to test :

cd packages/hardhat

echo '{"test": "value"}' > scripts/test.json

then create a new file in scripts/test.ts and try importing it:

import test from "./test.json";
console.log(test);

^ on main branch above should give you ts error:

"Cannot find module './test.json'. Consider using '--resolveJsonModule' to import module with '.json' extension. [2732]"

But on this branch it should work.

Also to see if script runs at runtime properly make sure you are cd packages/hardhat and then run :

yarn hardhat run scripts/test.ts

[carletex]

Great addition!