Add NodeJS options to device agent cmd line args docs

Added documentation for NodeJS command line options and how to pass them to the Device agent

Author: hardillb

docs/device-agent/running.md

@@ -51,6 +51,7 @@ Options
   -i, --interval secs
   -p, --port number
   -m, --moduleCache     Use local npm module cache rather than install
+  --node-options        Adds NodeJS command line arguments, can be specified multiple times
 
 Web UI Options
 
@@ -89,6 +90,12 @@ _Start the agent with a different working directory and the Web UI enabled_
 flowfuse-device-agent -d /path/to/working/directory -w --ui-user admin --ui-pass password --ui-port 8081
 ```
 
+_Start the agent with a larger NodeJS memory space and using the openssl CA certs_
+
+```bash
+flowfuse-device-agent -d /path/to/working/directory --node-options='--max_old_space_size=1024' --node_options='--use-openssl-ca'
+```
+
 ## Running behind a HTTP Proxy
 
 If the Remote Instance is behind a HTTP proxy, the agent can be configured to use the proxy by setting the `http_proxy`, `https_proxy` or `all_proxy` environment variables.
@@ -146,4 +153,4 @@ OS and Architecture as your target device, and then copy the modules on to your
 2. Place this file in an empty directory on your local device.
 3. Run `npm install` to install the modules. This will create a `node_modules` directory.
 4. On your target Remote Instance, create a directory called `module_cache` inside the Device Agent Configuration directory.
-5. Copy the `node_modules` directory from your local instance to the target instance so that it is under the `module_cache` directory.
+5. Copy the `node_modules` directory from your local instance to the target instance so that it is under the `module_cache` directory.