README.md in crtsh-rb-0.3.0 vs README.md in crtsh-rb-0.3.1

- old
+ new

@@ -1,8 +1,8 @@
 # crtsh
 
-[![Build Status](https://travis-ci.com/ninoseki/crtsh.svg?branch=master)](https://travis-ci.com/ninoseki/crtsh)
+[![Ruby CI](https://github.com/ninoseki/crtsh/actions/workflows/test.yml/badge.svg)](https://github.com/ninoseki/crtsh/actions/workflows/test.yml)
 [![Coverage Status](https://coveralls.io/repos/github/ninoseki/crtsh/badge.svg?branch=master)](https://coveralls.io/github/ninoseki/crtsh?branch=master)
 [![CodeFactor](https://www.codefactor.io/repository/github/ninoseki/crtsh/badge)](https://www.codefactor.io/repository/github/ninoseki/crtsh)
 
 [crt.sh](https://crt.sh) API client for Ruby.
 
@@ -13,19 +13,25 @@
 ```
 
 ## Usage
 
 ```ruby
+# Interact with Web API
 require "crtsh"
 
-# Interact with Web API
 api = Crtsh::API.new
 api.search("crt.sh")
 api.search("crt.sh", match: "LIKE")
 api.search("crt.sh", exclude: "expired")
 api.search("crt.sh", match: "LIKE", exclude: "expired")
+```
 
+```ruby
 # Interact with DB
+# Note that you have to install pg manually
+# gem install pg
+require "crtsh/db"
+
 db = Crtsh::DB.new
 sql = """
 SELECT digest(certificate.certificate, 'sha256') sha256
 FROM certificate_identity, certificate
 WHERE certificate.id = certificate_identity.certificate_id