Expand documentation for sending emails programatically

[aricooperdavis]

It would be nice to expand the documentation for how to send emails programatically; at the moment the documentation is essentially just the example code given in the swiftmailer documentation.

For example:

• Listing all of the possible set methods available, which are available in the Creating Messages section of the swiftmailer documentation. I think these are:
  • setBoundary
  • setBcc
  • setBody
  • setCharset
  • setChildren
  • setContentType
  • setCc
  • setDate
  • setDescription
  • setEncoder
  • setFormat
  • setFrom
  • setId
  • setMaxLineLength
  • setPriority
  • setReplyTo
  • setReturnPath
  • setSender
  • setSubject
  • setTo
  • setAuthMode
• Explaining how exceptions can be caught, i.e. a try-catch block accessing the error with $e->getMessage()

I'm happy to do this, but didn't want to put the work in and submit a pull request if there's not consensus that this is a good idea!

[rhukster]

I would totally accept a more detailed PR for the readme.

[rhukster]

Cleaning up old issues. please read: https://getgrav.org/blog/new-email-plugin

If you are interested in how to send email programmatically you can look in several places the Utils.php class in the email plugin, as well as the new Email.php class that are part of the symfony/mailer branch of the email plugin.