Provide "Run In Terminal" CodeLens for markdown content marked as shell

[angelozerr]

I noticed that you have integrate markdown support with language server in WWD.

It would be nice if WWD could provide a "Run In Terminal" CodeLens for markdown marked as shell

[Run In Terminal]
''' shell script
./mvnw quarkus:dev
'''

Click on Run In Terminal codelens could open a Terminal and execute the command.

IJ provides this feature and it is very nice

For instance when you create a Quarkus project, it generates a README with

```shell script
./mvnw quarkus:dev