Add a Rocket `tera` template example

[Luni-4]

It would be helpful to add this tera example for Rocket to shuttle-examples. It only requires to enable the tera features in rocket_dyn_templates. Is this feature going to work on shuttle if enabled?

[oddgrd]

Hey! Yes, it should work, but I'm not sure we need a whole new example for it, since Rocket already has an example for it.

[Luni-4]

Yes, you're right. Just wondering though whether an example in shuttle too could help in implementing a tera-template project more straightforward

[jonaro00]

Considering this repo is a great pool of templates to start from, diversifying in this direction makes it more likely that we have a starter template for everyone, at the cost of maintenance burden.

[Luni-4]

The current shuttle example could be changed as the Rocket example. So it is not necessary to add new examples and the maintenance burden will be reduced. The Rocket example uses both the templating mechanisms, so I presume a copy-paste approach should be sufficient, but I do not know the Shuttle effort, so I could be wrong