Add `Edit on Github` button to tutorials

[tmigot]

That's a feature encouraging contributors to edit tutorials.

[abelsiqueira]

Clarifying this issue:

• The tutorials are stored in JSOTutorials.jl
• The edit button should be on the individual tutorial page
• Clicking the button should lead to the JSOTutorials.jl file for that specific tutorial

[Jay-sanjay]

@abelsiqueira @dpo Wanted to be clear that for example I want to edit tutorials of this -https://jso.dev/tutorials/advanced-jsosolvers/ then I should point to this -https://github.com/JuliaSmoothOptimizers/JSOTutorials.jl/tree/main/tutorials/advanced-jsosolvers for editing. Please correct me if I am wrong.

[abelsiqueira]

@Jay-sanjay, that is correct. Possibly in the weaving (in JSOTutorials.jl), so it is automatically modified whenever we add new tutorials.