Vendor dependencies

Let's see how I like this workflow.

vendor/crossterm_winapi/docs/CONTRIBUTING.md

@@ -0,0 +1,4 @@
+# Contributing
+
+The `crossterm` crate
+[contributing guidelines](https://github.com/crossterm-rs/crossterm/blob/master/docs/CONTRIBUTING.md) applies.

vendor/crossterm_winapi/docs/known-problems.md

@@ -0,0 +1,10 @@
+# Known problems
+
+There are some problems I discovered during development. I don't think it has to do anything with
+the crossterm, but it has to do with how terminals handle ANSI or WinAPI. 
+
+## WinAPI
+
+- PowerShell does not interpret 'DarkYellow' and uses gray instead, cmd is working perfectly fine.
+- PowerShell inserts an '\n' (enter) when the program starts, this enter is the one you pressed when running the command.
+- After the program ran, PowerShell will reset the background and foreground colors.