Improve README.md

[kmturley]

Could we have a better readme explaining the steps for installation and the params for configuration?

Example from the mailchimp tap: https://github.com/singer-io/tap-mailchimp

tap-mailchimp

This is a Singer tap that produces JSON-formatted data following the Singer spec.

This tap:

• Pulls raw data from Mailchimp's API
• Extracts the following resources from Mailchimp:
  • lists
  • list_members
  • list_segments
  • list_segment_members
  • campaigns
  • reports_email_activity
    • Uses the Mailchimp batch API
  • unsubscribes
  • automations
• Outputs the schema for each resource

Configuration

This tap requires a config.json which specifies details regarding authentication and other options. access_token or (api_key and dc) are required

Config properties:

Property	Required	Example	Description
access_token	See note.	"20208d81..."	The access token from the OAuth2 flow.
api_key	See note.	"ac0ad1..."	The Mailchimp API key, if using API key auth instead of OAuth.
dc	See note.	"us14"	The Mailchimp data center, only requried when using API key auth.
start_date	Y	"2010-01-01T00:00:00Z"	The default start date to use for date modified replication, when available.
user_agent	N	"Vandelay Industries ETL Runner"	The user agent to send on every request.

Usage

To run tap-mailchimp with the configuration file, use this command:

tap-mailchimp -c my-config.json