[SKIP CI] improve README (#40)

README.md

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-# SubQl
+![open grant logo](https://raw.githubusercontent.com/w3f/General-Grants-Program/master/src/badge_black.svg)
+# Subquery
+Almost every substrate project has a need to process and query data.
+SubQuery is a open-source tool to provide a complete solution to this problem and will become core infrastructure for the Polkadot ecosystem.
+We expect it to solve how to Extract, Transform, Persist, and Query data intially, and then how to Connect and Present data in the future.
+
+SubQuery is NOT an ETL tool, the persisted data is minimized and shaped from the perspective of how it will be used.
+
+SubQuery aims to support all substrate-compatible networks.
+
+## Get Started
+### Step #1: Create a SubQuery project
+1. use `@subql/cli` tool we provide to create a SubQuery project
+  * it is written in typescript
+  * user needs to config the project, define a schema and implement mapping functions
+2. use `@subql/cli` to generate types from the given schema
+3. use `@subql/cli` to compile and pack the SubQuery project
+
+### Step #2: Run an indexer
+Prerequisites
+* A Postgres database
+* Non-archive full node. If storage query is used, then an archive node is required to extract chain data. [OnFinality](https://onfinality.io/api_service) provides an archive node with a generous free tier that should be more than able to cover most cases.
+* A moderately powerful computer to run an indexer in the background
+  Then start our `@subql/node` with the path of local SubQuery project as arguments, `@subql/node` will handle the rest.
+
+### Step #3: Run a Query Service
+We do have plan for a custom built graphql query service `@subql/query`, but in this stage we will use [Harura](https://hasura.io) to do the job.
+
+
+## Components
+Npmjs Packages to published:
+* `@subql/cli`
+* `@subql/node`
+* `@subql/common`
+* `@subql/types`
+
+## More Docs
+[Docs](https://onfinality-io.github.io/subql/)
+
+## Copyright
+
+Copyright © 2020-2021 OnFinality Limited authors & contributors