docs: fix markdown lint

README.md

@@ -3,7 +3,7 @@
 [![GoDoc](https://godoc.org/github.com/appleboy/drone-scp?status.svg)](https://godoc.org/github.com/appleboy/drone-scp)
 [![Build Status](https://cloud.drone.io/api/badges/appleboy/drone-scp/status.svg)](https://cloud.drone.io/appleboy/drone-scp)
 [![codecov](https://codecov.io/gh/appleboy/drone-scp/branch/master/graph/badge.svg)](https://codecov.io/gh/appleboy/drone-scp)
-[![Go Report Card](https://goreportcard.com/badge/github.com/appleboy/drone-scp)](https://goreportcard.com/report/github.com/appleboy/drone-scp) 
+[![Go Report Card](https://goreportcard.com/badge/github.com/appleboy/drone-scp)](https://goreportcard.com/report/github.com/appleboy/drone-scp)
 [![Docker Pulls](https://img.shields.io/docker/pulls/appleboy/drone-scp.svg)](https://hub.docker.com/r/appleboy/drone-scp/)
 [![micro badger](https://images.microbadger.com/badges/image/appleboy/drone-scp.svg)](https://microbadger.com/images/appleboy/drone-scp "Get your own image badge on microbadger.com")
 
@@ -161,7 +161,7 @@ drone-scp --host example1.com \
 
 ### Usage from docker
 
-#### Using public key
+Using public key
 
 ```bash
 docker run --rm \
@@ -176,7 +176,7 @@ docker run --rm \
   appleboy/drone-scp
 ```
 
-#### Using password
+Using password
 
 ```diff
 docker run --rm \
@@ -191,9 +191,7 @@ docker run --rm \
   appleboy/drone-scp
 ```
 
-#### Using ssh-agent
-
-Start your local ssh agent:
+Using ssh-agent, start your local ssh agent:
 
 ```bash
 eval `ssh-agent -s`
@@ -219,7 +217,7 @@ docker run --rm \
   appleboy/drone-scp
 ```
 
-#### Send multiple source or target folder and hosts
+Send multiple source or target folder and hosts
 
 ```bash
 docker run --rm \