Separate Ritchie formulas templates from the commons repository

[GuillaumeFalourd]

What would you like to be added:

• I would like to segregate responsibilities of each Ritchie repository, creating a ritchie-templates repository (like this one) which would contain existing formulas templates.

Why is this needed:

• We discussed a few months about the possibility to add Ritchie formulas templates to the CLI, to avoid the commons repository from being mandatory to create new formulas. But it seems this operation would change a lot of things, and should probably appear in the next LTS version (3.0.0).

• Having a specific repository for formulas templates would make it easier for people to contribute and understand how Ritchie actually works.

What is the impact

• This change would only impact the rit init command, where instead of adding the commons repository, the user would have to add the templates repository (currently, if we add any repository which contains the formulas templates, naming it commons, we can use the templates from this repository).

• Check this box if this issue needs a documentation update

[GuillaumeFalourd]

Repository created here: https://github.com/ZupIT/ritchie-templates
URL updated here: #1017
Add repo logic will be updated through: #1015