Missing documentation about setting up sdk locally

[lsampras]

Currently the documentation for hyperswitch-web only refers to setting up the demo app,

The environment variables mentioned above refer to those used in the demo app here.

There doesn't seem to be documentation about the variables used in actual SDK setup here.

referring to variables specifically here.

https://github.com/juspay/hyperswitch-web/blob/main/webpack.common.js#L11-L14

[PritishBudhiraja]

Addressed. Need few changes where ever we are using sdkEnv in our Jenkins Pipeline for running the scripts.
#335