Create Tutorials section, and move content into it

[pli888]

User story

As a student
I want all information to use Gibbon as a student to be in the Tutorials section
So that all information about using Gibbon as a student is in one section

As a staff member
I want all information to use Gibbon as a staff member to be in the Tutorials section
So that all information about using Gibbon as a staff member is in one section

As a parent
I want all information to use Gibbon as a parent to be in the Tutorials section
So that all information about using Gibbon as a parent is in one section

Acceptance criteria

Given I am on https://docs.gibbonedu.org/tutorials
When I look at the Gibbon documentation
Then I can see a Tutorials section
And I can see information to Use Gibbon as a student
And I can see information to Use Gibbon as a staff member
And I can see information to Use Gibbon as a parent
And I can see information to Set up my school in Gibbon
And I can see information to Manage students, staff and parents
And I can see information to Manage events and participants
And I can see information to Manage school finances
And I can see information to Manage assessments
And I can see information to Manage messaging and notifications