Create navbar

[sannawiklund]

• [x] In Pages > Shared > Layout.cshtml, create a navbar (the layout-page creates html that is viewable all over the application, no matter what page the user is on)
• [x] In the navbar, create a " <a href="/pagename" class="name-of-the-class"Sidnamn" for the following pages:
• Cart
• MyEvents
• Admin (when clicked, the authorization-feature reads if the person that is logged in is an admin or not. Through the admin-page all of the CRUD-options for events will then be avaliable)
• Review (or should this only be linked through eventdetails?)
• [x] Create a basic layout for the navbar

[sannawiklund]

I have added a static navbar in layout.cshtml that allows the user to always have the option to navigate arount the website no matter the page. All of the menu selections redirect to the corresponding razor page.

HTML and CSS is also added for styling.