Clarify doc and best practice

Author: aitikgupta

examples/text_labels_and_annotations/font_family_rc_sgskip.py

@@ -3,11 +3,17 @@
 Configuring the font family
 ===========================
 
-You can explicitly set which font family is picked up for a given font
-style (e.g., 'serif', 'sans-serif', or 'monospace').
+You can explicitly set which font family is picked up, either by specifying
+family names of fonts installed on user's system, or generic-families
+(e.g., 'serif', 'sans-serif', 'monospace', 'fantasy' or 'cursive'),
+or a combination of both.
+(see :doc:`font tutorial </tutorials/text/text_props>`)
 
-In the example below, we only allow one font family (Tahoma) for the
-sans-serif font style.  The default family is set with the font.family rcparam,
+In the example below, we are overriding the default sans-serif generic family
+to include a specific (Tahoma) font. (Note that the best way to achieve this
+would simply be to prepend 'Tahoma' in 'font.family')
+
+The default family is set with the font.family rcparam,
 e.g. ::
 
   rcParams['font.family'] = 'sans-serif'