Axis user guide (matplotlib#9323)

* deleted circled in green

* deleted space

* removed blue box

Author: tdpetrou

tutorials/introductory/usage.py

@@ -84,7 +84,7 @@
 # ------------------------------
 #
 # This is what you think of as 'a plot', it is the region of the image
-# with the data space (marked as the inner blue box).  A given figure
+# with the data space. A given figure
 # can contain many Axes, but a given :class:`~matplotlib.axes.Axes`
 # object can only be in one :class:`~matplotlib.figure.Figure`.  The
 # Axes contains two (or three in the case of 3D)
@@ -104,7 +104,7 @@
 # :class:`~matplotlib.axis.Axis`
 # ------------------------------
 #
-# These are the number-line-like objects (circled in green).  They take
+# These are the number-line-like objects. They take
 # care of setting the graph limits and generating the ticks (the marks
 # on the axis) and ticklabels (strings labeling the ticks).  The
 # location of the ticks is determined by a