Floating discussion title

**_1 Upvote**_ I noticed as threads/topics are getting larger than my poor short term memory is causing an issue on Flarum. I noticed that I would start reading a topic and completely forget which topic I am currently reading.

For this reason I am going to suggest adding the title of the topic somewhere static. I'm not sure the best place for it, but I was thinking on the right sidebar maybe just above the scroll thing whose feature name I can't remember. :P (although, I'm not sure that location works for mobile devices)

No file, test, or entry point is named. Start by locating the topic-reading view and its responsive/mobile layout, then determine a static placement for the topic title that remains visible while reading; done means the title is identifiable on desktop and mobile without disrupting the existing reading experience.

Written by the indexing model from the issue text.