Modified headers in building Citra to differ Debug and Release mode.

Building-for-Linux.md

@@ -33,7 +33,7 @@ cd citra
 
 The `--recursive` option automatically clones the required Git submodules too.
 
-### Building Citra:
+### Building Citra in Debug Mode (Slow):
 
 **Using gcc:**
 
@@ -74,7 +74,7 @@ Additionally, on Ubuntu,
 do `sudo apt-get install libc++abi-dev && sudo ln -s /usr/include/libcxxabi/__cxxabi_config.h /usr/include/c++/v1/__cxxabi_config.h`
 
 
-### Building Citra (Optimized):
+### Building Citra in Release Mode (Optimized):
 
 ```
 mkdir build && cd build