[README.md] Add doc for odbc transport

Author: abmusse

README.md

@@ -13,6 +13,7 @@
         - [idb-connector](#idb-connector)
         - [REST](#rest)
         - [SSH](#ssh)
+        - [ODBC](#odbc)
     - [ProgramCall](#programcall)
       - [Example](#example)
     - [CommandCall](#commandcall)
@@ -39,7 +40,7 @@ Before installing, download and install Node.js
 The Connection class is used to transport xml input and return xml output.
 
 #### Transports
-Supported transports include [idb-connector](https://github.com/IBM/nodejs-idb-connector), REST, and SSH.
+Supported transports include [idb-connector](https://github.com/IBM/nodejs-idb-connector), REST, SSH, and ODBC.
 
 ##### idb-connector
 The [idb-connector](https://github.com/IBM/nodejs-idb-connector) transport establishes a database connection and calls XMLSERVICE stored procedure.
@@ -126,6 +127,59 @@ const connection = new Connection({
 });
 ```
 
+##### ODBC
+The [ODBC](https://github.com/wankdanker/node-odbc/tree/v2.0) transport establishes a database connection and calls XMLSERVICE stored procedure.
+
+Before using the ODBC transport ensure all dependencies are installed.
+
+Ensure the IBM i Access ODBC driver is installed where you will be running Node.js.
+
+`TODO document installation`
+
+On the client side ensure `unixODBC` and `unixODBC-devel` are both installed.
+
+On IBM i this can be done with:
+
+`yum install unixODBC unixODBC-devel`
+
+Refer to [node-odbc](https://github.com/wankdanker/node-odbc/tree/v2.0#installation) for how this is done your OS.
+
+Also on the client side ensure the `IBM i Access ODBC Driver` is installed.
+
+`TODO document installation`
+
+To use the `ODBC` transport create an instance of Connection with:
+
+```javascript
+const connection = new Connection({
+  transport: 'odbc',
+  transportOptions: { host: 'myhost', username: 'myuser', password: 'mypassword'}
+});
+```
+
+Alternatively you can specify a [DSN](https://support.microsoft.com/en-us/help/966849/what-is-a-dsn-data-source-name) to use.
+
+Create an `.odbc.ini` file within your home directory and add additional configuration options.
+
+Refer to the [knowledge center](https://www.ibm.com/support/knowledgecenter/ssw_ibm_i_73/rzaik/connectkeywords.htm) for a list of valid options.
+
+A simple .odbc.ini file:
+
+```
+[*LOCAL]
+Driver=IBM i Access ODBC Driver
+UserID=myuser
+Password=mypass
+System=localhost
+```
+To use the `ODBC` transport with a DSN create an instance of Connection with:
+
+```javascript
+const connection = new Connection({
+  transport: 'odbc',
+  transportOptions: { dsn: '*LOCAL'}
+});
+```
 ### ProgramCall
 The ProgramCall class is used to call IBM i programs and service programs.