More verbose build instructions

BUILDING

@@ -1,5 +1,10 @@
 KenLM has switched to cmake
   cmake .
+  make -j 4
+But they recommend building out of tree
+  mkdir -p build && cd build
+  cmake ..
+  make -j 4
 
 If you only want the query code and do not care about compression (.gz, .bz2, and .xz):
   ./compile_query_only.sh

README.md

@@ -8,6 +8,12 @@ The website http://kheafield.com/code/kenlm/ has more documentation.  If you're
 
 ## Compiling
 Use cmake, see [BUILDING](BUILDING) for more detail.
+```bash
+mkdir -p build
+cd build
+cmake ..
+make -j 4
+```
 
 ## Compiling with your own build system
 If you want to compile with your own build system (Makefile etc) or to use as a library, there are a number of macros you can set on the g++ command line or in util/have.hh .