Doc: add batch application

[jbcaillau]

@agustinyabo can be for you 🙂

[jbcaillau]

@ocots can you pease add a pointer towards the (now removed) batch tutorial? was available, e.g., during FGS 2024

[ocots]

Here.

[!TIP] Choose a tag instead of a branch in the code.

[ocots]

@jbcaillau We need a template repository to facilitate adding applications.

[jbcaillau]

@ocots yes. if not already done, please issue this:

• CT-package repo template for additional packages
• CT-app repo template for apps

[ocots]

Are the appli and the package templates different?

[jbcaillau]

right, let's do the same. and an app could become a package to be used.