Update Readme to reflect cross-platform support (#3304)

* Remove Windows as specific prerequisite

* Add crossplatform announcement to docs

* [find_acquire.cmake] Fix ninja path for mac

* Another pass at making more platfrom neutral

* two additional fixes

* [osx] Ignore .DS_Store file. Fixes #3306

* Remove noexcept from BinaryParagraph()

* Add Bash shebang to bootstrap script

* Update gitignore to exclude the `vcpkg` binary (artifact of the build
script) from the git repo

* [sh] Change to #!/bin/sh

* [sh] Remove merge conflict lines

* [sh] permissions

* Since the auto_ptr is removed in c++17, so use unique_ptr to instead of it.

* [libxmlpp] Bump version in CONTROL file

* [readme] Add additional supported host platforms

* [readme] Slight packing and reformatting

1 files changed, 22 insertions, 10 deletions

diff --git a/README.md b/README.md
index 38d01601f..c35c597d9 100644
--- a/README.md
+++ b/README.md
@@ -1,36 +1,48 @@
 # Vcpkg <a href="#">![](https://devdiv.visualstudio.com/_apis/public/build/definitions/0bdbc590-a062-4c3f-b0f6-9383f67865ee/8476/badge)</a>
 
 ## Overview
-Vcpkg helps you get C and C++ libraries on Windows. This tool and ecosystem are currently in a preview state; your involvement is vital to its success.
+Vcpkg helps you manage C and C++ libraries on Windows, Linux and MacOS. This tool and ecosystem are currently in a preview state; your involvement is vital to its success!
 
 For short description of available commands, run `vcpkg help`.
 
 ## Quick Start
 Prerequisites:
-- Windows 10, 8.1, 7, Linux, or OSX
+- Windows 10, 8.1, 7, Linux, or MacOS
 - Visual Studio 2017 or Visual Studio 2015 Update 3 (on Windows)
 - Git
 - *Optional: CMake 3.10.2*
 
-Clone this repository, then run
+To get started:
 ```
-C:\src\vcpkg> .\bootstrap-vcpkg.bat
+> git clone https://github.com/Microsoft/vcpkg
+> cd vcpkg
+
+PS> .\bootstrap-vcpkg.bat
+Ubuntu:~/$ ./bootstrap-vcpkg.sh
 ```
+
 Then, to hook up user-wide integration, run (note: requires admin on first use)
 ```
-C:\src\vcpkg> .\vcpkg integrate install
+PS> .\vcpkg integrate install
+Ubuntu:~/$ ./vcpkg integrate install
 ```
+
 Install any packages with
 ```
-C:\src\vcpkg> .\vcpkg install sdl2 curl
+PS> .\vcpkg install sdl2 curl
+Ubuntu:~/$ ./vcpkg install sdl2 curl
 ```
-Finally, create a New Project (or open an existing one) in Visual Studio 2017 or 2015. All installed libraries are immediately ready to be `#include`'d and used in your project.
 
-The best way to use installed libraries with cmake is via the toolchain file `scripts\buildsystems\vcpkg.cmake`. To use this file, you simply need to add it onto your CMake command line as `-DCMAKE_TOOLCHAIN_FILE=D:\src\vcpkg\scripts\buildsystems\vcpkg.cmake`.
-For more information, see our [using a package](docs/examples/using-sqlite.md) example for the specifics.
+The best way to use installed libraries with CMake is via the toolchain file `scripts\buildsystems\vcpkg.cmake`. To use this file, you simply need to add it onto your CMake command line as `-DCMAKE_TOOLCHAIN_FILE=[vcpkg root]\scripts\buildsystems\vcpkg.cmake`.
+
+In Visual Studio, you can create a New Project (or open an existing one). All installed libraries are immediately ready to be `#include`'d and used in your project without additional configuration.
+
+For more information, see our [using a package](docs/examples/using-sqlite.md) example for the specifics. 
+
+Additional notes on macOS and Linux support can be found in the [official announcement](https://blogs.msdn.microsoft.com/vcblog/2018/04/24/announcing-a-single-c-library-manager-for-linux-macos-and-windows-vcpkg/).
 
 ## Tab-Completion / Auto-Completion
-`Vcpkg` supports auto-completion of commands, package names, options etc. To enable tab-completion in Powershell, use
+`vcpkg` supports auto-completion of commands, package names, options etc. To enable tab-completion in Powershell, use
 ```
 .\vcpkg integrate powershell
 ```