text/plain renders lang ... incorrectly, but renders ... ok

[jdanbrown]

MDH:

```
1
2
```

```scala
1
2
```

```python
1
2
```

text/plain part of email body:

Content-Type: text/plain; charset=UTF-8

1
2

12

12

[adam-p]

Markdown Here doesn't set the text/plain part of the email -- it's up the client to derive it from the HTML version.

One thing we could, in theory, do is massage the syntax highlighting output so that it gets converted to plaintext better. Except... then we'd have to figure out how each mail client (Gmail, Hotmail, Yahoo, Thunderbird, etc.) do their conversion. And then detect and fix when those clients change. Which is pretty unappealing.

(And if we have to change the Highlight.js code that we use, we wouldn't get approved by Mozilla. But maybe we could post-process the Highlight.js output. Anyway.)

The only platform that we can reasonably set the text/plain stream for is Thunderbird. I'm going to close this issue, but if you have opinions about how the text/plain should look there, add your input to issue #63.

[jdanbrown]

Oh jeez, I didn't realize you weren't emitting the text/plain directly. What a pain.

I expect this kind of issue will become more important over time, but I understand why it wouldn't be high prio for you now. Thanks Adam.

[adam-p]

I agree that its desirable (and would be cool) to set the test/plain to the raw MD. Once upon a time I even tried de-prettifying and reading the Gmail JavaScript to see if I could hook in or monkeypatch it somehow. But... failed.

If you -- or anyone -- knows how to do something like that I'd certainly like to hear about it. It would probably be a pain to maintain, but maybe we could fail gracefully (i.e., into the state we're in now). Issue #50 also requires some Gmail source hackery.