[DOC] Add rudimentary README.
Merge pull request #2 from gatewayd/CRUD-routes

Set up /database routes
[TASK] Append /database view links to navbar and fix route declarations
[TASK] Add External Accounts to navbar and implement its view
[TASK] Create /new routes for adding entries to specific databases and implement External Transactions view
[TASK] Implement Gateway Transactions view
[TASK] Implement remaining views: Gateway Transactions, KYC Data, Policies, Ripple Addresses, Ripple Transactions, Users
[TASK] Implement controllers for database views: Ripple Addresses, Ripple Transactions, Users
[TASK] Complete Users view table headings, implement Policies view controller, add create/read functions for database routes (policies, users, external_accounts, external_transactions), and start database/users/new view and controller
[TASK] Add create functions for Ripple Addresses and Ripple Transactions in API and implement form and controller for New Ripple Addresses view
[TASK] Implement forms (views and controllers) for creating new: External Accounts, External Transactions, Ripple Addresses, Ripple Transactions in databases
[TASK] Fix POST request bodies, enable redirecting to /database/? views after submitting create request, implement API call/view/controller for: New External Transactions, New Policies, and New KYC Data