Documentation Fixes

[DogeDark]

Fixes:

• Desktop guide provides a GitHub search query to find examples using dioxus_desktop. You no longer need to import dioxus_desktop so this query results in nothing.
• Desktop guide does not mention how to run the app without hot reload.
• This code source was broken.
• The first mention of needing r# for the type attribute is on the User Input page. Should mention it in the RSX page Attributes section too.
• Duplicate text: "it could be stored in use_signal, use_signal, or a constant." Here
• Web page eval example says Dioxus desktop and not Dioxus web.
• Added a small section to the mobile guide to ensure you set your build variant in Android Studio.
• Adds a little more context and information to make the hacker news project a little more accessible.

[DogeDark]

I believe CI is failing because of native core stuff. Evan's PR has it fixed so I'll wait for that to merge and then pull master back into this one.

Edit: I was wrong. Both are having the same issue.