[lldb][Docs] Various style improvements to the tutorial (#90594)

* Replace "we" with either "you" (when talking to the reader) or "lldb"
(when talking about the project).
* Refer to lldb as lldb not LLDB, to match what the user sees on
the command line (I am going to come back later and put the proper name in places where it's talking about the projects themselves)
* Remove a bunch of contractions for example "won't". Which don't (pun
intended) seem like a big deal at first but even I as a native English
speaker find the text clearer with them expanded.
* Use RST's plain text highlighting for keywords and command names.
* Split some very long lines for easier editing in future.