add explanation FAQ

Author: gabrielaznar

doc/source/install.rst

@@ -94,7 +94,9 @@ FAQs
     import sys
     sys.path.append('path/to/climada_python')
 
-* ModuleNotFoundError; python library not found. It might happen that the pip dependencies of *env_climada.yml* (the ones specified after ``pip:``) have not been installed in the environment *climada_env*. You can then install manually these dependencies as follows::
+* ModuleNotFoundError; some python library is not found. It might happen that the pip dependencies of *env_climada.yml* (the ones specified after ``pip:``) have not been installed in the environment *climada_env*. You can then install them manually one by one as follows::
 
     source activate climada_env
     pip install library_name
+
+  where ``library_name`` is the missing library.