guides/developer/Development-environment.md

@@ -19,6 +19,8 @@ The following will build and setup a self-contained environment for you:
 The ```ARACHNI_BUILD_ENV=development``` env tells the build-scripts to preserve
 development headers of all the libraries it installs so that you'll be able to
 install more gems inside that env if need be.
+(If you don't plan on installing extra gems you can leave the ```ARACHNI_BUILD_ENV```
+variable undefined and save some space.)
 
 Finally, if you are using RVM, put this in your ```.rvmrc``` file:
 
@@ -32,3 +34,5 @@ Finally, if you are using RVM, put this in your ```.rvmrc``` file:
 
 If not using RVM you'll have to run the above manually when working from the
 terminal while developing Arachni.
+(I suggest putting the above in a shellscript named ```arachni-setenv.sh```
+and running it from the same terminal you plan to use to test/run/dev with Arachni.)