fix trailing whitespace
a step towards uniform code directives
fixup the way exercise arrays are displayed
better use of lists and syntax
scale the numpy indexing picture a bit better
be explicit about code-blocks
better scaling of second indexing diagram
strip traling whitespace
uniform code-blocks in the numpy operations section
syntax
remove trailing whitespace
uniform prompts

The more advanced stuff was not changed, since it is repeated in the advanced
numpy section and will be deleted from this section soon.
prompt fixes etc..
move duplicate content from intro numpy to advanced numpy
intro/numpy/elaborate_arrays.rst: fix failing doctests, apparently trailing whitespace is needed
bring back in the intersphinx mappings

Somehow the intesphinx mapping for numpy is bust.
intersphinx and link to advanced numpy
Merge branch 'overhaul/intro/numpy'

* overhaul/intro/numpy:
  intersphinx and link to advanced numpy
  bring back in the intersphinx mappings
  intro/numpy/elaborate_arrays.rst: fix failing doctests, apparently trailing whitespace is needed
  move duplicate content from intro numpy to advanced numpy
  prompt fixes etc..
  uniform prompts
  remove trailing whitespace
  syntax
  uniform code-blocks in the numpy operations section
  strip traling whitespace
  better scaling of second indexing diagram
  be explicit about code-blocks
  scale the numpy indexing picture a bit better
  better use of lists and syntax
  fixup the way exercise arrays are displayed
  a step towards uniform code directives
  fix trailing whitespace