Contract name starting from a small alphabet generates invalid hardhat typings

I have a contract name of the form `xToken`. The typings are generated for `XToken` which can be imported but the hardhat counterparts don't work.

```ts
hre.ethers.getContractFactory('XToken'); // for this typings are present but hardhat expects xToken
hre.ethers.getContractFactory('xToken'); // this is the intended use but typings not present by default
```