Remove most templates

[anton-trunov]

For instance, the Deployable trait is deprecated.

[novusnota]

Most of those templates use either Deployable trait or text receivers, so we should either fix them or take new ones.

I propose we just remove those examples and start all over. Let's take:

1. "Hello, World" and Counter examples from "Learn Tact in Y minutes", after this task is done (~today)
2. Examples from the defi-cookbook — currently it features only the Jettons, but they are quite important, so we can highlight all those examples

And that's about it.

As a bonus, we can add the following examples in-between the ones I gave earlier if we'll remove the Deployable and text receivers from them: "A Contract Deploying Another", "Parent-Child Relationship", "Communicating with Sub-Contract", "Authenticating Children".

What do you think @rahulyadav-57 @anton-trunov?

[rahulyadav-57]

Yes, I agree with you, @novusnota. We should create a new set of templates from different categories and difficulty levels.