Improve examples

[zrzka]

Currently there're top level examples (crossterm) and examples in subcrates (crossterm_cursor/example). This is causing issues like:

• I can't run subcrate examples with cargo run --example cc_cursor
• Lot of duplicated code
• Build warnings (examples with the same name)
  • Will be hard error in the future
  • I prefixed them in the 2018 edition #222 as a temporary workaround

My proposal is to:

• Remove all subcrate examples
• Improve top level examples (merge them with the subcrate ones)

This is based on the fact that most people will use crossterm crate only (with features) directly.

[zrzka]

Reply from #222:

I'm really doubting that we might want to remove the examples from the sub crates and instead use those in /examples, because all those examples are mostly duplicated with the only difference being the namespaces.

IMHO this can be solved by splitting imports in the root level example and adding a comment that crossterm should be replaced with crossterm_... if a subcrate is used directly. What bothers me:

• code duplication
• you can't run subcrate examples with simple cargo run --example
• it's not clear that these examples differ in the namespace only and when I saw them for the first time (directory structure, not the code itself) I thought that they're different

I'll show you what I mean with this issue & comment in a separate branch. I can delete it if you wont like it, no problem.

[TimonPost]

Exactly I prefer that as well because code duplication is a real pain. Just comment in the /examples/README.md, or in the example file would be good enough to tell the user that namespaces might vary on the crate they are using.

[TimonPost]

I am going to open a PR that removes all duplicated examples in subcrates

[zrzka]

Fixed by #225