Update Windows Support Instructions in README.md

[mdqst]

In the "Windows Support" section of the blockchain-wallet-v4-frontend/README.md file, the following command is listed:

npm install -g windows-build-tools

However, it’s important to note that the windows-build-tools package is no longer supported. It is now recommended to manually install the required dependencies, such as Python 2.7 and Visual C++ Build Tools.

The README might be using outdated information. I suggest updating this section to reflect the current installation process for Windows development dependencies.