Documentation improvements

[heruan]

During DX Tests part of the Hilla client-side library documentation wasn't clear to the tester, in particular:

Export the single sign-on context in the App.tsx file.

What is "single sign-on context"? A brief explanation of what it is might improve the reader experience.

[tamasmak]

Adding more feedback and improvement suggestions from DX tests:

• Create a link to the protected endpoint Hilla documentation from the Protect Example Endpoint section.
• Check the React documentation and how they provide the small code examples. Do they split the code into small code examples or do they have longer code examples?
• Add a hint in the documentation that now you should test the buttons at the related section.
• Move the custom redirect path tip down in the related section.
• Add more description for the protectRoutes function usage and add some code examples on how to use the custom redirect path.
• Fix the type in the “Gather the hasAccess function and add a filter to the routes that checks for authentication.” at the “routes that checks” part.
• The code examples suggest copying the useSsoContext hook many times. Add some more explanation why the user needs to do that.
• Mention that a server restart is needed whenever the application properties are changed.