Add support for Text quick replies

[crccheck]

Why are we doing this?

We made a way to do Image + quick replies but not Text + quick replies. This adds that missing message type, it also deprecates the old ImageQuickReply helper in favor of plain Text and Image + .quickReplies() method. Adding quick replies isn't really a new message type, it's a modification of existing types. The syntax from the tests and README look like:

const text = new Text('Where are you?').quickReplies([{ content_type: 'location' }])

closes #60

Did you document your work?

README is updated. I wonder if this should move to the wiki though, the README is getting heavy.

How can someone test these changes?

Steps to manually verify the change:

1. npm i
2. npm t

What possible risks or adverse effects are there?

• none

tech debt increases slightly but can improve when ImageQuickReply is removed. There's also some potential for a DRY refactor

What are the follow-up tasks?

• release minor version bump

Are there any known issues?

none

Did the test coverage decrease?

new code is covered, increasing coverage

[stripethree]

Looking good. 👍 Tests pass, no questions on the code as it looks straightforward.

README is updated. I wonder if this should move to the wiki though, the README is getting heavy.

Perhaps it is time for s split? Maybe theREADME can keep the project description & prior art and the wiki has everything else?

[crccheck]

I may just start writing more in the wiki then when it meets a certain quality and dupes the README, delete the README version