Rename bank connector and add documentation

[SuhasBharadwajK]

The pull request contains the following changes:

1. Documentation of both client/frontend (india-banking) and server/backend (india-banking-connector).
2. Rename "Bank Connector" in india-banking to "Backend Connector".

Reason for rename:

The "Bank Connector" in this repository, india-banking, is in fact a connector to the India Banking backend/server, and not directly to the bank. While it is in fact linked to a bank account, the API Key and Secret expected are of a Frappe user from the instance whose IP is whitelisted with the bank. Hence, it makes sense to call it a Backend Connector, even more so because there are other Bank Connector DocTypes in india-banking-connector, which is confusing.

Edit: Reverted the name change part as requested by @Vigneshsekar and created a new PR #95.

[Vigneshsekar]

Thanks for your contribution.

Except for the renaming, we would love to take the documentation changes merged immediately.

Is it possible for you to split the PR into two?

[SuhasBharadwajK]

I can, but the documentation is based on the renamed entities. I'll have to change it again. In fact, the precise reason for the rename is the confusion I thought might be caused for those reading the documentation.

[Vigneshsekar]

IMO, In the server app, these are named as connectors, and so renaming them is not recommended at this stage.

[SuhasBharadwajK]

@Vigneshsekar

IMO, In the server app, these are named as connectors, and so renaming them is not recommended at this stage.

While I agree with the first part, I would argue on the contrary to the second on two points:

First, the connectors in the server app make sense to be named with the banks because they connect with the banks, as the names suggest. In the client app, however, the connectors do not talk with the banks at all! Even in a shared deployment, the app makes an additional request to itself using the credentials. There is no bank server involved anywhere in this transaction.

For this reason, I thought of several names: Bank Backend Connector, Backend Bank Connector, Banking Backend Connector, India Banking Backend Connector, etc. At the end of the day, a name that suggests what the connector does while being simple seemed to be the best way to go. And hence: Backend Connector.

Second, changing the name at this stage seems the most sensible option to me precisely because of the small number of forks (most of them probably dormant). Once this repository grows big, which I definitely foresee, given the excellent work you guys have put in and the impact of an application like this, it'll be a significant and breaking change. Please discuss amongst yourselves and let me know. Until then, I have closed this PR.