ENH: Improved suggestions for environments

[mcocdawc]

Currently the additionalInserts for environments are specified like this:

    latex:
      figure:
        text: 'figure'
        additionalInsert: '\\caption{title}'

It would be great to have similar behaviour as the self defined snippets by atom.
This means that it should be possible to specify a point where the cursor jumps to upon pressing tab.
Something along the line of:

    latex:
      figure:
        text: 'figure'
        additionalInsert: '\\caption{${1:title}}'

Unfortunately this does not work and I don't know enough coffescript to implement it myself.

[ashthespy]

Can do, a bit busy right now - so no promises on timeline :-)