support RMarkdown blocks

[fredcallaway]

Hey there! I'm trying to set up an alternative to RStudio for editing RMarkdown files using Sublime Text and radian. I use a mixture of Python and R. I wonder if it would be possible to add a feature to detect rmd style blocks and use the appropriate interpreter? That is, if I paste in

```{python}
x = [1,2,3]
```

it should be equivalent to typing

~
x = [1,2,3]
[BACKSPACE]

Similarly, if you type

```{r}
x <- c(1,2,3)
```

it should just be equivalent to just

x <- c(1,2,3)

[fredcallaway]

Bump. I could probably implement this myself and making a pull request if you are open to it.

[randy3k]

I am not entirely sure if we should handle it in radian. It sounds like the duty of a text editor plugin.

[fredcallaway]

OK, well for me that plugin would be SendCode. I guess the natural place to do it would be in CodeSender. But I do think that the functionality (e.g. replacing ```{python} with ~ is more specific to radian than it is to the code sending mechanism. And perhaps someone might want to just paste an rmarkdown script into radian?