Tweak documenting process

### How it works?

There are 2 ways to upgrade documentation published on [OCF Documentation]:

* Push any change on **develop** branch will force update of **develop** version on the [OCF Documentation] website;

* Create a tag, this will create a version with tag name on the [OCF Documentation] website.

There are 2 ways to upgrade documentation published on the [OCF Documentation] website:

  * Push any change on **develop** branch will force update of the **develop** version on the [OCF Documentation] website;

  * Create a tag, this will create a version with the tag name on the [OCF Documentation] website.

### Branches

2. Create an issue on [GitLab](https://labs.etsi.org/rep/ocf/documentation/-/issues);

3. Create a new branch with source from **develop**;

4. Update documentation:

   1. ***Remember to update index.md with new functionalities for the latest version***;

   2. New test plan is defined? **Update test plan documentation**

    1. **Remember to update index.md with new functionalities for the latest version**;

    2. If a new test plan is defined, remember to **update the test plan documentation**

5. Check if errors are being produced by ``mkdocs`` [locally](#getting-started);

6. Push changes to branch;

7. Create a merge/pull request;