chore: update build instructions

doc/make/index.md

@@ -8,12 +8,11 @@ Requirements
 Platform-Specific Setup
 -----------------------
 
-- [Linux (Ubuntu)](ubuntu-16.04.md)
+- [Linux (Ubuntu)](ubuntu.md)
 - [Windows (msys2)](msys2.md)
 - [Windows (Visual Studio)](msvc.md)
 - [macOS (homebrew)](osx-10.9.md)
-- Linux/macOS ([Nix](https://nixos.org/nix/)): call `nix-shell` in the project root
-- [Emscripten: lean.js](emscripten.md)
+- Linux/macOS ([Nix](https://nixos.org/nix/)): Call `nix-shell` in the project root. That's it.
 
 Generic Build Instructions
 --------------------------

doc/make/msys2.md

@@ -6,7 +6,7 @@ Lean for Windows
 
 A native Lean binary for Windows can be generated using [msys2].
 It is easy to install all dependencies, it produces native
-64/32-binaries, and supports a C++11 compiler.
+64/32-binaries, and supports a C++14 compiler.
 
 
 ## Installing dependencies
@@ -18,7 +18,7 @@ It has a package management system, [pacman][pacman], which is used in Arch Linu
 Here are the commands to install all dependencies needed to compile Lean on your machine.
 
 ```bash
-pacman -S mingw-w64-x86_64-gcc mingw-w64-x86_64-cmake python make git
+pacman -S make python mingw-w64-x86_64-cmake mingw-w64-x86_64-ccache git
 ```
 
 Then follow the [generic build instructions](index.md) in the [msys2] shell, using

doc/make/osx-10.9.md

@@ -40,7 +40,7 @@ Required Packages: CMake, GMP
     brew install gmp
 
 
-Optional Packages: ninja
-------------------------
+Recommended Packages: CCache
+----------------------------
 
-    brew install ninja
+    brew install ccache

doc/make/ubuntu-16.04.md

@@ -1,10 +0,0 @@
-Installing Lean on Ubuntu 16.04
--------------------------------
-
-### Basic packages
-
-    sudo apt-get install git libgmp-dev cmake
-
-### Optional Packages: ninja
-
-    sudo apt-get install ninja