Add tutorials for reference

[imanishbarnwal]

Make a new file name "tutorials.md" and add tutorials regarding Flutter, and other required tech stacks involved in making this project so that beginners can get the idea of proceeding with the app.

[brainless-coder]

I would like to work on this issue

[Anushka-shukla]

@brainless-coder I am assigning you this issue can go ahead and add the links to tutorials in a descriptive and beginner-friendly way. Do add tutorials for flutter, GitHub and maybe for Adobe Xd too as it will be used to design the wireframe of the application.

[jambsantos]

Hi, I 'd like to contributing translating for portuguese and spanish. Can i?