message: More key docs
diff: @@ -148,7 +148,9 @@ Sometimes there may be endpoints in the API which have not been added to this pa
  The config.json includes an optional field `privateKeyString`. Set this as an ENV var outside the of `xero-node` and pass it in with the config.
  -Private keys are of a particular format. Here is an example:
  +Private keys are of a particular format. If your using this method it needs to be a single string, and it must include the `-----BEGIN RSA PRIVATE KEY-----` and matching end part. Be sure to include a `\n` after this first line and before the last line, as well as `\` characters at the end of lines.
  +
  +Here is an example:
  ```
  let xeroKeyString =
  @@ -159,6 +161,12 @@ sajklsdalksdasdlkdslkdwlkdwskldskldslkd\n\
  -----END RSA PRIVATE KEY-----";
  ```
  +Here is a handy command to generate this string from your .pem file:
  +
  +```
  +$ awk 'NF {sub(/\r/, ""); printf "%s\\n",$0;}' privatekey.pem
  +```
  +
  ## Migration from V2
  The biggest change is the number of function calls you have to make to complete your task. This is consistant across all endpoints. It's not JSON in and JSON out. your object never gets modified:
  