Better template for wrapping in environments

Imho the most typical use case is a starting text like

```
We are going to make a list:

first item
second item
third item

and we are done!
```

Then we select the block “first item … third item”, including the EOLs (using double-click and drag on MacOS e.g.). With this commit, hitting the key combo to wrap the selection in an environment will produce

```
We are going to make a list:

\begin{env}
first item
second item
third item
\end{env}

and we are done!
```

whereas it used to produce before the change

```
We are going to make a list:

\begin{env}
first item
second item
third item

\end{env}
and we are done!
```

I argue that the former is better than the latter.