docs: README

Author: RuslanBergenov

README.md

@@ -6,6 +6,7 @@ A [Singer](https://singer.io) target that writes data to Google BigQuery.
 
 ## Contents
 - [Contact](#contact)
+- [Dependencies](#dependencies)
 - [How to use it](#how-to-use-it)
     - [Step 1: Enable Google BigQuery API](#step-1-enable-google-bigquery-api)
     - [Step 2: Authenticate with a service account](#step-2-authenticate-with-a-service-account)
@@ -25,6 +26,29 @@ A [Singer](https://singer.io) target that writes data to Google BigQuery.
 
 Email: `[email protected]`
 
+## Dependencies
+
+Install requirements, using either of the two methods below.
+
+**Method 1**
+```
+pip install -r requirements.txt 
+```
+
+**Method 2**
+
+Alternatively, you can run the following command. It runs *setup.py* and installs target-bigquery into the env like the user would. **-e** emulates how a user of the package would install requirements.
+```
+pip install -e .
+```
+**Additional development and testing requirements**
+
+Install additional dependencies required for development and testing. 
+```
+pip install -r dev-requirements.txt
+
+```
+
 ## How to use it
 
 ### Step 1: Enable Google BigQuery API