add some minimal docs about SSH executor

docs/Guides/SSHExecutor.md

@@ -0,0 +1,41 @@
+## Generic SSH Executor
+
+## Introduction
+
+While Bpipe supports many different resource managers, you may encounter situations where you simply
+need to execute a command on a fixed remote server. It can also be the case that you wish to use
+a resource manager that is not directly supported by Bpipe, and in these situations you orchestrate
+allocation of the resources outside of Bpipe but need Bpipe to simply run a command on the target host.
+
+In these scenarios, the `SSH Executor` may be useful. It allows you to simply specify a host name and
+SSH credentials, and Bpipe will then use SSH to execute the command in your pipeline on the remote
+host. In addition to executing the remote command, the SSH Executor also supports functionality
+to transfer files to and from the remote host, if it is not integrated with the source host with
+a shared file system.
+
+## Configuration
+
+To run an SSH Executor, configure the `SSH` type in the executor setting, and then set the hostname
+and username in a sub-section called `ssh_executor`:
+
+```
+executor="SSH"
+
+ssh_executor {
+  hostname="my.compute.server"
+  user="myuser"
+}
+```
+
+These settings will cause Bpipe to try to run commands on the remote server using SSH to
+execute them.
+
+## Keys
+
+- can set keypair setting in config
+
+## File Transfer
+
+Set `transfer=true` at higher level to cause Bpipe to copy files to and from the target host
+using SSH. Note that the user provided must have permissions to create the directory path
+that the pipeline is running in on the target host, as well as copy files to and from it.

mkdocs.yml

@@ -91,6 +91,7 @@ nav:
   - Integration with JMS / Queuing Systems: Guides/JMS.md
   - Using Bpipe with Amazon Web Services (AWS/EC2): Guides/AWS.md
   - Using Bpipe with Google Cloud (GCS): Guides/GoogleCloud.md
+  - Using generic SSH to execute commands: Guides/SSHExecutor.md
   - Running Commands in Containers: Guides/Containers.md
 - Examples:
   - Paired End Alignment: Examples/PairedEndAlignment.md